Want to Lower Your Blood Pressure? Count Not Just Calories, But Food Quality, Too

In an analysis of data from the randomized CALERIE-2 trial, researchers showed that long-term calorie restriction (CR) not only reduced blood pressure in participants, but also improved diet quality—and it was this improvement that partly explained the differences in how much blood pressure dropped. Simply put, the “better” the diet was in the context of a moderate energy deficit, the greater the cardiovascular benefit.

Background

• Calorie restriction (CR) in humans has already shown benefits. In the second phase of the randomised CALERIE trial (2 years, healthy non-obese adults), moderate CR resulted in sustained weight loss and improvements in a range of cardiometabolic markers, including reductions in systolic and diastolic blood pressure, CRP and improved insulin sensitivity. This was confirmed by the publication of the CALERIE-2 results in the Lancet Diabetes & Endocrinology (2019).
• CR affects not only weight, but also “biological age.” Subsequent studies on the CALERIE-2 biobank showed changes in epigenetic metrics of aging against the background of long-term CR, which supports the idea of systemic effects of such a strategy.
• Diet quality itself influences blood pressure. Pattern diets such as the DASH, Mediterranean, and “healthy” mixed diets are associated with lower blood pressure and better cardiovascular outcomes; meta-analyses show clinically significant mean BP reductions with dietary interventions.
• The gap so far: While the CR in CALERIE-2 reduced blood pressure on average, the response varied widely between participants. An open question was whether these differences were explained by how the quality of their diet changed during the long-term CR, and not just by the magnitude of the calorie deficit and weight loss.

What kind of work is this?

• Journal: Current Developments in Nutrition (2025).
• Data: CALERIE-2 is the largest randomized trial to date of 2 years of moderate calorie restriction in healthy, non-obese adults. In a new analysis, the authors linked changes in diet quality (as measured by food intake records) to changes in systolic and diastolic blood pressure over the course of the intervention.
• Context: The CALERIE-2 seminal paper already showed that 2 years of moderate CR improves the profile of cardiometabolic risk factors (including lower BP, CRP, and improved insulin sensitivity). The new paper answers the question “why does the effect differ among individuals?” and what role not only calorie deficit but also diet composition plays in this.

How was the “quality of the diet” assessed?

The researchers used detailed food records (six-day food diaries) before and during the intervention and calculated diet quality indices - composite scores that reflect how closely the diet approaches patterns such as DASH/HEI (more vegetables, fruits, whole grains and legumes; less added sugar, saturated fat and sodium).

Main results

• Participants on CR improved diet quality and reduced BP on average, but the effect varied widely between individuals.
• The more the diet quality index improved, the more the blood pressure dropped. In other words, calorie deficits worked better when accompanied by smart food choices, rather than simply “smaller portions.”

These findings fit well with the broader literature: high-quality dietary patterns (HEI/AHEI/DASH) are associated with a lower risk of hypertension and cardiovascular events, and short- and medium-term meta-analyses of calorie restriction show clinically significant reductions in systolic and diastolic BP.

Why is this important?

1. Practical takeaway: If you choose a moderate calorie restriction strategy, diet quality is critical. Moving to a more “DASH-like” diet may enhance the antihypertensive effect. 2) Personalization: Variation in response to CR is partly explained by food, not just calorie deficit and weight loss - this argues for individualized recommendations.

What exactly does it mean to “improve the quality of your diet”?

• More: vegetables and fruits (daily), legumes (3-4 times a week), whole grains, nuts/seeds, low-fat dairy; fish 1-2 times a week.
• Less: sodium (target <2.3g salt as sodium), red and processed meats, salt

Limitations of the study

• CALERIE-2 is in healthy, non-obese adults; tolerability and effects in the elderly/people with underlying medical conditions may differ.
• Nutritional assessment is based on self-reports (even very detailed ones), which always carries the risk of errors.
• The analysis is associative: it shows the contribution of diet quality to the variability of the response, but does not “prove” that simply replacing foods without CR will give exactly the same effect on BP.

How to apply in practice

• Aim for a moderate calorie deficit (your doctor/dietitian can help you choose a safe level).
• At the same time, adjust your diet to the DASH/HEI pattern (see above) - this will increase the chance of lowering blood pressure and overall cardiovascular benefits.
• Monitor protein and micronutrients (CR ≠ nutrient deficiency).
• CR is not suitable in pregnancy/breastfeeding, eating disorders, BMI < 18.5, a number of chronic conditions - act under the supervision of a specialist.
  These recommendations are consistent with the basic results of CALERIE-2 and reviews on the effect of CR and diet quality on blood pressure and risks.

Source: CALERIE-2 analysis in Current Developments in Nutrition (2025): “The Impact of Diet Quality During Long-Term Caloric Restriction on Blood Pressure: An Analysis of CALERIE™ 2.” DOI: 10.1016/j.cdnut.2025.106086