Endocrinologist for obesity: diagnosis, testing, treatment, and weight control

Obesity is now viewed not simply as "excess body weight," but as a chronic, recurring disease associated with metabolism, hormonal regulation of appetite, fat distribution, heredity, sleep, psycho-emotional factors, medications, and the environment. Therefore, when assessing obesity, an endocrinologist evaluates not only weight but also the causes of weight gain, the risks of type 2 diabetes, hypertension, lipid metabolism disorders, sleep apnea, fatty liver disease, and other complications. [1]

According to the World Health Organization, in 2022, 2.5 billion adults were overweight, and more than 890 million adults were obese; among adults 18 years and older, overweight occurred in 43%, and obesity in 16%. These figures are important for clinical practice because obesity has become one of the most common reasons for visiting doctors related to metabolism, cardiovascular risk, and chronic disease prevention. [2]

The classic benchmark for initial assessment is the body mass index: The World Health Organization defines overweight in adults as a body mass index of 25 kg/m² or higher, and obesity as a body mass index of 30 kg/m² or higher. However, this indicator does not indicate exactly how much fat is in the body, where it is located, or how much it has already impacted health, so modern assessment should not be limited to just one weight figure. [3]

In 2024, the European Association for the Study of Obesity proposed a framework in which obesity is viewed as a chronic disease associated with excess or maldistributed fat deposits, and diagnosis should take into account not only body mass index but also waist circumference, waist-to-height ratio, complications, functional status, and treatment goals. This approach is closer to the work of an endocrinologist, as it addresses not the question of "how much weight should I lose," but rather the question of "what disorders need to be prevented or already treated." [4]

In 2025, the Lancet Diabetes and Endocrinology committee further proposed a distinction between preclinical obesity, where excess fat is present but organ function is still intact, and clinical obesity, where excess fat is already associated with organ dysfunction or limitations in daily activity. This doesn't eliminate the need for a body mass index, but makes the diagnosis more medical: an endocrinologist evaluates not just kilograms, but the entire risk profile and existing consequences. [5]

What does an endocrinologist evaluate?	Why is this necessary?
Body mass index	Rapid initial assessment of body weight category
Waist circumference and waist-to-height ratio	Assessment of central obesity and cardiometabolic risk
Glucose, glycated hemoglobin, lipids	Search for prediabetes, type 2 diabetes, and dyslipidemia
Blood pressure	Identification of cardiovascular risk
Thyroid function	Excluding hypothyroidism as a factor in weight gain
Medication, sleep, nutrition, psycho-emotional state	Finding the causes that support weight gain or interfere with weight loss

The table reflects a modern approach: obesity is assessed not only by body weight, but by a combination of anthropometry, metabolic disorders, hormonal factors, complications and individual treatment goals. [6]

When should you see an endocrinologist if you are obese?

You should consult an endocrinologist if your body mass index has reached 30 kg/m² or higher, if there is rapid weight gain without an obvious cause, if weight gain is accompanied by fatigue, drowsiness, swelling, menstrual irregularities, decreased libido, increased blood pressure, elevated blood sugar, or a family history of type 2 diabetes. In such situations, the doctor's task is not simply to confirm obesity, but to understand whether it is associated with hormonal imbalances, medications, sleep disturbances, insulin resistance, or complications of adipose tissue. [7]

Consultation with an endocrinologist is especially important in cases of abdominal obesity, when fat is predominantly deposited in the abdominal area. NICE recommends using body mass index as a practical indicator, but emphasizes that it is not a direct measure of central obesity; in adults with a body mass index below 35 kg/m², the waist-to-height ratio should also be used to assess the risk of type 2 diabetes, hypertension, and cardiovascular disease. [8]

Consulting an endocrinologist is also warranted if a person has already attempted weight loss through diet and physical activity, but the reduction was insufficient or the weight quickly returned. Endocrine and metabolic guidelines emphasize that obesity requires long-term treatment, not a short-term "diet for a few weeks," because biological mechanisms of appetite, energy expenditure, and weight restoration often work against long-term results. [9]

Consultation is especially necessary for people with prediabetes, type 2 diabetes, high blood pressure, lipid metabolism disorders, sleep apnea, fatty liver disease, polycystic ovary syndrome, infertility, low testosterone in men, or suspected Cushing's syndrome. In these cases, weight loss may not be a cosmetic goal, but rather part of treatment for a condition that is already affecting blood vessels, the liver, the reproductive system, sleep, and quality of life. [10]

Unusual signs that warrant more urgent examination include: pronounced purple stretch marks on the skin, muscle weakness in the hips and shoulders, easy bruising, a sharp increase in blood pressure, a new blood sugar imbalance, rapid fat gain in the face and torso with relatively thin limbs. These symptoms do not automatically indicate Cushing's syndrome, but they require a targeted evaluation, as endocrine causes of obesity are less common than simple multifactorial obesity, but they cannot be overlooked. [11]

Situation	Why do you need an endocrinologist?
Body mass index of 30 kg/m² and above	It is necessary to evaluate the complications and choose a long-term strategy.
Body mass index of 27 kg/m² or higher plus diabetes, hypertension, or sleep apnea	There may be indications for drug therapy
Rapid weight gain	Endocrine and medicinal causes must be excluded.
Abdominal obesity	High probability of metabolic risk
Menstrual irregularities, infertility, excessive hair growth in women	Polycystic ovary syndrome or another endocrine disorder may be present.
Drowsiness, snoring, sleep apnea	Obstructive sleep apnea must be ruled out.
High blood sugar	Need an assessment for prediabetes or type 2 diabetes?
Unsuccessful attempts at weight loss	We need a medical program, not another short diet.

The table shows the practical reasons for referring to an endocrinologist: it is important for the doctor to determine not only the degree of obesity, but also what complications already exist, what causes can be eliminated, and what level of treatment is needed for a particular person. [12]

What happens at the initial appointment?

An initial appointment with an endocrinologist begins with a detailed discussion: when the weight gain began, how the person's weight has changed over the years, whether there have been any sudden fluctuations, what diets have been tried, how the person sleeps, what medications the person takes, whether there are nighttime overeating, bouts of uncontrollable hunger, depressive symptoms, chronic pain, or limited mobility. This discussion is necessary because obesity is often maintained not by a single factor, but by a combination of diet, sleep, stress, medications, heredity, and concomitant diseases. [13]

The doctor then measures height, weight, and waist circumference, calculates the body mass index, and, if necessary, the waist-to-height ratio. NICE recommends that adults with a body mass index below 35 kg/m² use this ratio as a practical estimate of central obesity, and consider a value of 0.5 or higher as a signal of increased risk, meaning the waist should be less than half the height. [14]

An endocrinologist evaluates signs of complications: blood pressure, swelling, shortness of breath during exertion, daytime sleepiness, snoring, joint pain, symptoms of fatty liver disease, signs of carbohydrate metabolism disorders, skin changes, symptoms of hypothyroidism, reproductive complaints, and psycho-emotional state. This is important because obesity treatment becomes more effective when the goal is formulated not only as "minus kilograms," but also as improving blood sugar, blood pressure, sleep, liver, joints, and daily activity. [15]

A separate part of the consultation is a medication review. Some medications can promote weight gain or hinder weight loss, including some hypoglycemic agents, some antidepressants, antipsychotics, glucocorticoids, and certain medications for the treatment of arterial hypertension. The endocrinologist will not discontinue them arbitrarily, but can suggest more weight-neutral alternatives to the attending physician if safe. [16]

Good obesity care shouldn't be limited to blame or the phrase "eat less." Current guidelines emphasize a patient-centered and anti-stigmatizing approach: obesity is a chronic condition, requiring physicians to discuss treatment goals, limitations, availability, risk of side effects, and the person's readiness for change without demeaning or pressuring them. [17]

Primary reception block	What does the doctor clarify?
History of weight	Age of onset of weight gain, maximum weight, attempts to lose weight
Nutrition	Eating habits, late-night snacking, sugary drinks, overeating
Dream	Snoring, pauses in breathing, daytime sleepiness
Medicines	Drugs that may increase weight gain
Family history	Obesity, type 2 diabetes, early cardiovascular events
Hormonal symptoms	Thyroid gland, cortisol, sex hormones
Complications	Blood pressure, blood sugar, lipids, liver, joints, sleep apnea
Patient goals	Health, mobility, fertility, diabetes management, quality of life

The table helps us understand why an endocrinologist appointment takes longer than a simple weigh-in: to choose treatment, we need to see the biological, behavioral, medicinal, and social factors that support obesity. [18]

What tests and examinations does an endocrinologist prescribe?

A basic examination for obesity typically focuses on identifying complications and risk factors: fasting glucose, glycated hemoglobin, lipid profile, liver enzymes, creatinine with an assessment of kidney function, uric acid, blood pressure, and sometimes a urine test for albumin and creatinine. This set of tests is not just for show, but for the early detection of disorders that may not cause obvious symptoms for years but already increase the risk of heart attack, stroke, and kidney and liver damage. [19]

Thyroid function is almost always checked, as the European Society of Endocrinology recommends testing obese patients for thyroid dysfunction. It's important to explain realistically to the patient: hypothyroidism can contribute to weight gain, but it usually doesn't completely explain severe obesity, and treating hypothyroidism alone rarely leads to significant weight loss without a comprehensive treatment program. [20]

Tests for cortisol, testosterone, prolactin, sex hormones, and other hormonal indicators are not prescribed to everyone, but rather when clinically suspected. The European Society of Endocrinology emphasizes that testing for hypercortisolism, male hypogonadism, and female gonadal dysfunction is indicated when the corresponding symptoms are present, as obesity itself can alter certain hormonal indicators and lead to false interpretations. [21]

When polycystic ovary syndrome (PCOS) is suspected in women, an endocrinologist evaluates cycle irregularities, signs of androgen excess, acne, excessive hair growth, androgenic hair loss, metabolic risks, and reproductive plans. The 2023 international guidelines emphasize that this syndrome requires a comprehensive assessment because it is associated not only with the ovaries but also with metabolism, mental health, fertility, and the long-term risk of type 2 diabetes. [22]

If you experience snoring, pauses in breathing during sleep, morning headaches, severe daytime sleepiness, or persistently elevated blood pressure, an endocrinologist may refer you for a sleep study. This is important because obstructive sleep apnea is a common complication of obesity and also a factor that worsens weight control, blood pressure, fatigue, and metabolic health. [23]

Direction of examination	Examples of analyses and assessments	What helps to identify
Carbohydrate metabolism	Fasting glucose, glycated hemoglobin	Prediabetes, type 2 diabetes
Lipid metabolism	Total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides	Atherosclerotic risk
Liver	Alanine aminotransferase, aspartate aminotransferase, ultrasound examination as indicated	Fatty liver disease
Thyroid gland	Thyroid-stimulating hormone, free thyroxine as indicated	Hypothyroidism or other disorders
Cortisol	Tests only if clinically suspected	Cushing's syndrome
Reproductive hormones	By gender, age and symptoms	Polycystic ovary syndrome, hypogonadism
Dream	Questionnaires, night breathing tests according to indications	Obstructive sleep apnea
Kidney and vascular risk	Creatinine, urine albumin, blood pressure	Kidney damage and cardiovascular risk

The table reflects the principle of reasonable examination: all patients need basic metabolic tests, and extended hormonal diagnostics are carried out for symptoms that truly indicate a specific endocrine disease. [24]

What endocrine causes of obesity does a doctor look for?

Obesity is most often a multifactorial disease, not the result of a single hormone. The World Health Organization emphasizes that in most cases, obesity is associated with a combination of environmental, psychosocial, and genetic factors, while in some patients, specific causes can be identified, including medications, diseases, limited mobility, medical interventions, or monogenic syndromes. [25]

Hypothyroidism is often considered the primary cause of obesity, but this is a common oversimplification. The American Thyroid Association explains that an underactive thyroid can cause some weight gain, but with hypothyroidism, much of the weight gain is due to salt and water retention, and severe obesity is rarely explained by the thyroid gland alone. [26]

Cushing's syndrome is a rarer but clinically significant cause of weight gain. It is suspected not only in cases of excess weight, but also in the presence of a combination of central obesity, muscle weakness, thin skin, easy bruising, widespread purple stretch marks, osteoporosis, persistent hypertension, blood sugar abnormalities, and characteristic changes in appearance. With these signs, an endocrinologist orders specific tests for excess cortisol. [27]

In women, obesity is often associated with polycystic ovary syndrome, which is characterized by irregular cycles, signs of androgen excess, ovulation difficulties, acne, male-pattern hair growth, and increased metabolic risk. The 2023 international guidelines emphasize the need for comprehensive care, as this condition affects reproductive, metabolic, and psychological health. [28]

Obese men may experience decreased testosterone levels, but this does not always indicate a primary gonad disease. The European Society of Endocrinology notes that hormonal imbalances in obesity can be a consequence of the adipose tissue itself and often improve with weight loss. Therefore, evaluation and treatment should be based on symptoms, repeated accurate measurements, and the overall clinical picture. [29]

Possible endocrine cause	What are the warning signs?	What does an endocrinologist do?
Hypothyroidism	Chilliness, drowsiness, dry skin, constipation, swelling	Checks thyroid function
Cushing's syndrome	Purple stretch marks, muscle weakness, bruising, high blood pressure, high sugar	Orders tests for excess cortisol
Polycystic ovary syndrome	Irregular cycles, acne, male-pattern hair growth, infertility	Assesses androgens, ovulation and metabolic risk
Male hypogonadism	Decreased libido, erectile dysfunction, loss of muscle mass	Tests testosterone according to the rules and looks for the causes
Drug-induced weight gain	Weight gain after starting a new drug	Analyzes therapy and offers safe alternatives
Rare genetic forms	Very early onset of obesity, severe hunger from childhood, family history	Referral for specialized assessment

The table shows that the endocrinologist is not looking for “one magic hormone,” but rather compares symptoms, tests, and weight dynamics in order not to miss treatable causes and, at the same time, not to prescribe unnecessary tests without indications. [30]

How an endocrinologist formulates a diagnosis and treatment goals

The modern goal of obesity treatment is not only weight loss but also health improvement: reducing waist circumference, lowering blood pressure, improving glucose, lipids, sleep, liver function, mobility, joint pain, and quality of life. The American Association of Clinical Endocrinology, in its 2025 update, emphasizes a shift from a "weight-centered" approach to treating obesity disease, where complications, metabolic health, and individual goals are important. [31]

The primary goal is often expressed as a 5-10% weight loss, as even this reduction can improve blood sugar, blood pressure, lipids, and joint stress. However, with type 2 diabetes, sleep apnea, severe abdominal obesity, or severe fatty liver disease, more significant and sustained weight loss may be required, so the treatment plan depends on complications, not just the starting weight. [32]

An endocrinologist should discuss a realistic treatment horizon. Obesity is prone to relapse, so a successful program typically involves long-term monitoring, regular follow-up visits, adjustments to diet, physical activity, medications, sleep, and treatment of comorbidities, rather than a one-time diet prescription. [33]

When making a diagnosis, it is important not to stigmatize the patient. Obesity guidelines increasingly emphasize that a blame-based approach impairs communication with the physician, reduces treatment adherence, and prevents the patient from seeking help; therefore, a competent endocrinologist discusses obesity as a medical condition, not as a character flaw. [34]

A well-defined goal is specific: for example, to lose 7% of body weight in 6 months, reduce waist circumference, lower glycated hemoglobin, improve walking ability, reduce snoring and daytime sleepiness, prepare for pregnancy, or reduce the risk of prediabetes progressing to type 2 diabetes. This approach helps patients see the medical significance of treatment and not judge success solely by the number on the scale. [35]

Goal of treatment	What is being monitored?
Reduction of fat mass	Body weight, waist circumference, clothing dynamics, body composition according to indications
Improving carbohydrate metabolism	Glucose, glycated hemoglobin
Reducing cardiovascular risk	Blood pressure, lipids, smoking, physical activity
Improving sleep	Snoring, pauses in breathing, daytime sleepiness
Liver protection	Liver enzymes, signs of fatty liver disease
Improving the quality of life	Endurance, pain, mobility, self-care
Maintaining the result	Long-term visits and weight gain prevention

The table underlines the main principle: obesity treatment should be assessed by medical outcomes, not just short-term weight loss. [36]

Treatment: Nutrition, exercise, sleep, and behavioral support

Diet, physical activity, and behavioral modification remain the foundation of treatment, but this doesn't mean simply giving a person a blanket list of no-nos. The Endocrine Society emphasizes that diet, physical activity, and behavioral modification should be part of all obesity treatment approaches, with medications and surgery used as adjuncts when a basic program alone is insufficient or when the risk of complications is high. [37]

The diet is designed to be sustainable over the long term: a moderate energy deficit, sufficient protein, vegetables, and dietary fiber are essential, as are limiting sugary drinks, ultra-processed foods, and frequent energy-dense snacks. An endocrinologist may work with a nutritionist, especially if the patient has type 2 diabetes, chronic kidney disease, fatty liver disease, gout, eating disorders, or is preparing for bariatric surgery. [38]

Physical activity is necessary not only for burning calories, but also for maintaining muscle mass, improving insulin sensitivity, blood pressure control, sleep, mood, and functional independence. For obesity, the program should begin at a safe level: walking, aquatic exercise, low-impact strength training, gradually increasing the load, and adapting to joint pain or shortness of breath. [39]

Sleep and stress are an integral part of treatment. Lack of sleep, working nights, sleep apnea, chronic anxiety, and depressive symptoms can increase hunger, decrease activity, worsen blood sugar control, and interfere with adherence to a plan, so an endocrinologist should inquire about sleep, mood, and eating behavior as seriously as about nutrition. [40]

Behavioural support helps maintain results: regular self-monitoring, meal planning, addressing triggers for overeating, gradual goals, relapse prevention, and support visits. NICE recommends monitoring the medication's effectiveness while simultaneously reinforcing behavioural recommendations and treatment adherence through regular monitoring. [41]

Treatment component	Practical purpose	Why is this important?
Nutrition	Sustainable energy deficit without extreme restrictions	Helps reduce fat mass and maintain the results
Protein and strength training	Maintaining muscle mass	Reduces the risk of weakness and slow metabolism
Aerobic activity	Increased endurance and energy expenditure	Improves blood pressure, sugar and sleep
Dream	Correction of sleep deprivation and sleep apnea	Reduces metabolic load
Behavioral therapy	Controlling habits and triggers	Reduces the risk of weight gain
Regular visits	Correction of the plan	Allows you to avoid wasting months with ineffective tactics

The table shows that the basic treatment for obesity is not "willpower" but a structured medical program in which nutrition, movement, sleep and behavior work together.[42]

When are obesity medications needed?

Medication is considered if a person is obese or overweight with complications, and basic measures are insufficient or the risk of complications requires more aggressive treatment. The Endocrine Society states that pharmacotherapy can be used for a body mass index of 27 kg/m² or higher in the presence of comorbidities, or for a body mass index above 30 kg/m², but only as an adjunct to diet, physical activity, and a behavioral program. [43]

In recent years, the approach to medications has changed significantly due to drugs that affect the incretin system—the hormonal signals from the gut and brain involved in appetite, satiety, and glucose regulation. In 2025, the World Health Organization issued the first global guidelines for the use of such drugs for obesity in adults, emphasizing that they should be part of comprehensive long-term treatment, not a stand-alone replacement for diet, exercise, and medical monitoring. [44]

In Europe, modern weight management medications include semaglutide, liraglutide, tirzepatide, naltrexone with bupropion, and orlistat, but specific availability and indications vary by country, registration, contraindications, comorbidities, and reimbursement policies. NICE's prescribing guidance for adults lists tirzepatide, semaglutide, liraglutide, and orlistat as options that should be used in conjunction with calorie reduction and increased physical activity. [45]

Semaglutide and tirzepatide are currently in a unique position because they produce greater weight loss in clinical trials than older drugs. The European Medicines Agency reports that in studies of semaglutide, adults with obesity or overweight and complications experienced an average weight loss of about 15% over 68 weeks in one of the pivotal studies, while tirzepatide, in a study of more than 2,500 adults, achieved an average weight loss of at least 15% in a dose-dependent manner over 72 weeks. [46] [47]

Medications require monitoring for side effects and contraindications. For example, for semaglutide, the European Medicines Agency lists common gastrointestinal adverse events, including nausea, vomiting, diarrhea, constipation, and abdominal pain; for naltrexone and bupropion, restrictions are important in uncontrolled hypertension, seizures, and certain psychiatric conditions. [48] [49]

Active ingredient	What is the point of the appointment?	What is important to control
Semaglutide	Reduced appetite, weight loss support, benefits for some cardiometabolic risks	Tolerability, gastrointestinal symptoms, contraindications
Tirzepatide	Effects on appetite, body weight, and glucose via 2 hormonal pathways	Tolerance, glucose, gastrointestinal symptoms
Liraglutide	Daily injection therapy for weight management	Efficacy after 12 weeks at full or tolerated dose
Naltrexone with bupropion	Effects on appetite and eating behavior	Pressure, contraindications, tolerance
Orlistat	Decreased absorption of fat in the intestines	Gastrointestinal effects, fat-soluble vitamins as indicated

The table is not a self-treatment regimen: the choice of drug depends on the diagnosis, complications, contraindications, tolerability, drug interactions, reproductive plans and the availability of the drug in a particular healthcare system. [50]

When an endocrinologist refers to a bariatric surgeon

Bariatric and metabolic surgery is not seen as an "easy way out," but rather as a treatment for severe obesity and related conditions when the expected benefits outweigh the risks and the patient is prepared for long-term follow-up. NICE recommends that adults be referred for a comprehensive assessment of suitability for bariatric surgery if their body mass index is 40 kg/m² or above, and if their body mass index is between 35 and 39.9 kg/m² and they have significant underlying medical conditions that would benefit from weight loss. [51]

NICE lists cardiovascular disease, hypertension, idiopathic intracranial hypertension, fatty liver disease, obstructive sleep apnea, and type 2 diabetes as conditions that may improve after bariatric surgery. This means that the decision to undergo surgery is made not only based on weight, but also on a combination of the degree of obesity, complications, failure of previous treatment, and willingness to undergo lifelong monitoring. [52]

The 2022 international guidelines from the American Society for Metabolic and Bariatric Surgery and the International Federation for the Surgery of Obesity expanded this approach: metabolic and bariatric surgery is recommended for people with a body mass index greater than 35 kg/m², regardless of the severity of comorbidities, and should be considered in people with metabolic diseases with a body mass index of 30–34.9 kg/m². This reflects accumulating evidence on the impact of surgery not only on weight but also on diabetes and long-term risks. [53]

An endocrinologist is important before surgery because they help evaluate diabetes, thyroid function, vitamin and mineral deficiencies, medications, the risk of hypoglycemia, blood pressure, and other factors. After surgery, an endocrinologist or a specialized team is involved in long-term monitoring because nutrient absorption, medication doses, body weight, glucose levels, and the risk of deficiencies all change. [54]

Surgery does not replace the need for nutrition, activity, protein monitoring, vitamins, minerals, and psycho-emotional support. NICE emphasizes that pre-operative assessment by a multidisciplinary team, including specialists capable of conducting medical, nutritional, psychological, and surgical assessments, is necessary, and that post-operative long-term follow-up, including annual reviews, is required. [55]

When discussing surgery	What is assessed before referral?
Body mass index of 40 kg/m² and above	General surgical risk, willingness for lifelong observation
Body mass index 35-39.9 kg/m² plus significant complications	Diabetes, sleep apnea, hypertension, liver disease, cardiovascular risk
Insufficient effect of drugs and basic therapy	Reasons for inefficiency, alternatives, patient expectations
Type 2 diabetes mellitus with obesity	Possibility of metabolic effect of surgery
Suspected eating disorder	Psychological and psychiatric assessment
Planning a pregnancy	Timing of surgery, nutrition and safety

The table shows that a referral to a surgeon is not an automatic decision based on a single BMI number, but rather a comprehensive assessment involving an endocrinologist, nutritionist, psychologist, surgeon, and other specialists. [56]

How is treatment effectiveness monitored?

Monitoring begins with predetermined goals: weight, waist circumference, blood pressure, glucose, glycated hemoglobin, lipids, exercise tolerance, sleep, well-being, and side effects of therapy. Tracking only weight can miss important improvements, such as lower blood sugar, lower blood pressure, improved sleep, or reduced joint pain. [57]

With drug therapy, regular visits are particularly important in the first months. The Endocrine Society's educational materials on pharmacological treatment of obesity emphasize that frequent monitoring improves outcomes, and NICE recommends regular assessment of the effect of medications, reinforcement of behavioral recommendations, and support for adherence to treatment. [58] [59]

If a drug is not effective or is poorly tolerated, the endocrinologist should not continue the ineffective regimen indefinitely. For example, the European Medicines Agency recommends stopping treatment in adults with liraglutide if a reduction of at least 5% of baseline body weight is not achieved after 12 weeks at the maximum or maximum tolerated dose; naltrexone with bupropion also requires stopping treatment if there is insufficient response after 4 months. [60] [61]

After weight loss, maintaining the results is important. NICE emphasizes the need to support people who stop taking weight-control medications, as without a long-term plan, weight gain is possible, especially if the factors that contributed to the obesity are not addressed. [62]

Adjusting a plan does not mean failure. In a chronic illness, it is normal for a physician to change the dose, medication, goals, or monitoring intensity, add sleep apnea treatment, adjust hypoglycemic therapy, refer to a dietitian, or discuss bariatric surgery; this is part of a managed care process, not a sign of "weak motivation." [63]

What do they control?	How often do they usually rewatch?	Why is this necessary?
Body weight and waist circumference	At each follow-up visit	Assessment of fat mass dynamics
Pressure	Regularly, often at home	Reducing cardiovascular risk
Glucose and glycated hemoglobin	By baseline risk and presence of diabetes	Management of prediabetes and type 2 diabetes
Lipid profile	By cardiovascular risk	Correction of atherosclerotic risk
Side effects of medications	At each visit after the start of therapy	Safety and commitment
Sleep and daytime sleepiness	If you have complaints or sleep apnea	Controlling the factor that interferes with weight loss
Quality of life and activity	Regularly	Assessing the real benefits of treatment

The table emphasizes that successful treatment of obesity is a managed observation of several medical indicators, rather than a one-time prescription of a drug or diet. [64]

Common mistakes made by patients and doctors

The first mistake is to assume that an endocrinologist is obligated to find a "hormonal cause" in every obese individual. In practice, most cases of obesity are multifactorial, and hormonal disorders are much less common; the physician's task is to reasonably rule out important endocrine conditions, but not to turn the examination into an endless search for a non-existent cause. [65]

The second mistake is treating weight alone, ignoring complications. If a person already has prediabetes, type 2 diabetes, sleep apnea, hypertension, fatty liver disease, or joint pain, then treatment should be aimed at improving these conditions, not just achieving an "ideal" body weight. [66]

The third mistake is prescribing medications without a monitoring plan. Modern medications can be effective, but they require an assessment of contraindications, side effects, drug interactions, reproductive plans, and efficacy criteria; without monitoring, a person risks either unnecessary side effects or prolonged treatment without sufficient benefit. [67]

The fourth mistake is stopping treatment immediately after achieving results. Obesity is prone to relapse, so after weight loss, a maintenance plan is needed: nutrition, activity, sleep, medication management, regular visits, and early response to gradual weight gain. [68]

The fifth mistake is stigmatizing the patient. Blame, shame, and harsh language do not improve weight loss but hinder treatment; modern endocrinology guidelines increasingly emphasize the need for a respectful, personalized approach that takes into account the biology of obesity, complications, and the patient's real-life circumstances. [69]

Error	What is dangerous?	What is the correct way?
Search only for "hormones"	You may miss meals, sleep, medications and complications	Evaluate all factors
Focus only on weight	You may not notice any improvement in your health or progression of complications.	Monitor your sugar, blood pressure, waist size, and sleep.
Buy medications on your own	Risk of contraindications and side effects	Prescription and supervision by a physician
Stopping treatment after the first successes	High risk of weight gain	Performance Maintenance Plan
Considering obesity as a weakness	Shame and refusal to help	View obesity as a chronic disease
Prescribe the same diet to everyone	Low commitment	Individual plan

The table shows that in obesity both oversimplification and excessive unnecessary testing are harmful; the optimal path is a personalized and controlled medical program. [70]

Frequently asked questions

Should I see an endocrinologist if I'm simply overweight but my test results are normal? Yes, if my weight continues to increase, I have abdominal obesity, a family history of type 2 diabetes, high blood pressure, snoring, sleep disturbances, or unsuccessful weight loss attempts. Even with normal test results, a doctor can assess my risks, help me develop a plan, and determine how often I need to be monitored. [71]

Can the thyroid gland be the sole cause of obesity? Usually not. Hypothyroidism can cause moderate weight gain, but much of this gain is due to fluid and salt retention, while severe obesity often has multifactorial causes. [72]

What tests are absolutely necessary for everyone? Typically, indicators of carbohydrate metabolism, lipids, liver function, kidney function, blood pressure, and thyroid function are needed, but the exact list depends on age, gender, complaints, medications, heredity, and known medical conditions. Extensive hormonal tests for cortisol or sex hormones are not needed for everyone, but rather if clinical signs are present. [73]

Should semaglutide or tirzepatide be prescribed immediately? The decision depends on the indications, contraindications, drug availability, comorbidities, tolerability, cost, and willingness to undertake long-term follow-up. These drugs can result in significant weight loss, but should be used as part of a comprehensive program and not as a substitute for a medical plan. [74] [75]

If the medication is helping, will it have to be taken forever? Obesity is a chronic condition, so many people require long-term therapy or a long-term maintenance plan. If the medication is discontinued, the doctor should discuss diet, activity, weight management, and alternative methods for preventing weight gain beforehand. [76]

When is surgery necessary? Referral for bariatric surgery is usually considered in cases of severe obesity, particularly with a body mass index of 40 kg/m² or higher, or 35-39.9 kg/m² with severe complications, as well as in selected cases of metabolic diseases with a lower body mass index. The decision is made after evaluation by a multidisciplinary team and commitment to lifelong monitoring. [77] [78]

Is it possible to treat obesity without medication? Yes, for some people, lasting results are possible with diet, activity, sleep, and behavioral support, especially if obesity is detected early and complications have not yet manifested. However, if there is a high risk or previous attempts have been ineffective, an endocrinologist may suggest drug therapy or referral to a specialized service. [79]

Why does an endocrinologist ask about sleep and mood? Sleep, sleep apnea, depression, anxiety, chronic stress, and eating behavior can contribute to weight gain and interfere with treatment. Without assessing these factors, a person may prescribe the right diet or medication, but receive poor results due to an unnoticed cause. [80]

Key points from experts

Francesco Rubino, Professor of Metabolic and Bariatric Surgery at King's College London, chaired The Lancet Diabetes and Endocrinology Commission on the Definition and Diagnosis of Clinical Obesity. The commission's key practical thesis was that obesity should be diagnosed not only by body mass index, but also by excess body fat, its distribution, organ dysfunction, and its impact on daily life. [81]

Luca Busetto, a physician and obesity researcher and one of the authors of the European Association for the Study of Obesity 2024 framework, emphasizes the shift toward understanding obesity as a chronic disease of adipose tissue. The practical implication for patients: treatment should be long-term, individualized, and focused on health, not just a quick reduction in weight. [82]

Karl Nadolsky, an endocrinologist and chair of the American Association of Clinical Endocrinology's 2025 obesity algorithm, is involved in the update, which emphasizes personalized and complication-focused treatment. The key message is that therapy intensity should be determined based on disease severity, complications, metabolic risk, and the patient's goals, not just body mass index. [83]

Caroline M. Apovian, MD, professor of medicine and chair of the Endocrine Society's Task Force on Pharmacological Treatment of Obesity, contributed to the guideline, which considers medications as an adjunct to diet, physical activity, and behavioral therapy. The practice statement: weight-loss medications should not be prescribed in isolation, because the best results are achieved with comprehensive and monitored treatment. [84]

Andreea Ciudin, an endocrinologist and co-author of the European Association for the Study of Obesity's 2025 guidelines for pharmacotherapy, is associated with a new approach in which semaglutide and tirzepatide are considered first-line drugs for many patients with obesity and its complications. The practical point: drug choice increasingly depends not only on the desired weight loss but also on specific complications—type 2 diabetes, sleep apnea, cardiovascular risk, liver disease, or joint pain. [85]

Result

An endocrinologist is needed for obesity not to "find the culprit hormone" in each patient, but to medically assess the disease: the degree and type of obesity, the risk of diabetes and cardiovascular complications, thyroid function, possible rare endocrine causes, the influence of medications, sleep, nutrition, and psycho-emotional factors. This approach is consistent with the modern understanding of obesity as a chronic disease requiring long-term and respectful treatment. [86]

The endocrinologist's primary value is personalization: one person may benefit from a structured program of nutrition, activity, and monitoring; another may require drug therapy; a third may require treatment for sleep apnea, adjustments to hypoglycemic medications, or a referral to a bariatric surgeon. Modern medicine is increasingly moving away from the idea of a "one-size-fits-all diet" and is increasingly focusing on complications, safety, quality of life, and sustainable results. [87]