Intermittent fasting outperforms daily calorie restriction on blood pressure and long-term estimates of cardiovascular risk.

Intermittent fasting outperforms daily calorie restriction on blood pressure and long-term estimates of cardiovascular risk.

Real-world data suggests that a 5:2 fasting approach may demonstrate modest superiority over daily calorie restriction in terms of key blood pressure measurements and estimated cardiovascular risks. This highlights its potential as a viable option for adults who are overweight or obese.

In a recent study published in the journal Scientific Reports published, researchers compared the effects of two dietary strategies on metabolic markers, cardiovascular disease risk estimates, and blood pressure in obese and overweight adults. Compared to daily calorie restriction, 5:2 intermittent fasting resulted in modestly greater improvements in systolic blood pressure and pulse pressure, as well as greater reductions in cardiovascular risk scores based on body mass index. At the same time, triglyceride levels only fell within the intermittent fasting group and not significantly more than with calorie restriction.

Cardiovascular risk and nutritional interventions

Cardiovascular disease (CVD) is a leading cause of death worldwide, causing nearly 20 million deaths each year. Although genetic factors and age influence the risk of CVD, lifestyle factors, including obesity, play an important role.

Nutritional interventions play a central role in the prevention and treatment of cardiovascular risks associated with obesity. One of the helpful strategies is intermittent fasting, which is increasingly coming into focus as a flexible alternative to daily calorie restriction.

The 5:2 intermittent fasting pattern, which involves significant calorie restriction on two non-consecutive days per week, is often considered easier to implement than continuous calorie restriction. Previous studies suggest that it may improve lipid levels, blood pressure, body weight and blood sugar regulation.

Biologically, intermittent fasting could improve cardiovascular health by increasing insulin sensitivity, Inflammation reduces and promotes favorable hormonal and autonomic changes that lower blood pressure and heart rate. However, these mechanisms are largely hypothetical, and most evidence comes from tightly controlled studies, which limits practical relevance.

Study structure and participant selection

Using data from Iran's National Obesity Registry, researchers compared the real-world effects of 5:2 intermittent fasting and daily calorie restriction on cardiovascular risk factors and estimated long-term CVD risk scores in obese and overweight adults.

Adults aged 18 to 65 years with a body mass index (BMI) of at least 25 kg/m and at least 3 months of follow-up were included in the study. Participants were excluded if they were breastfeeding, taking medication for weight loss, had diseases affecting metabolism, or did not follow their prescribed diet.

Participants were assigned to a diet, either a 5:2 intermittent fasting regimen or a daily calorie restriction regimen, not randomly, but according to standard clinical protocols and physician guidance. In the intermittent fasting group, women consumed 500 kcal and men 600 kcal on two non-consecutive days per week, with normal energy intake on the remaining days. The calorie restriction group followed a daily diet that had an energy deficit of 500-1000 kcal. Macronutrient composition was similar in both groups, and all diets were monitored by trained dietitians.

Measurements and risk assessment

Anthropometric measures, blood pressure indices, laboratory values ​​including glucose and lipid profiles, and physical activity were assessed at baseline and after three months. Long-term cardiovascular risk was estimated using BMI-based and lipid-based 30-year Framingham risk scores and other atherogenic indices. Statistical analyzes compared changes within and between groups, taking into account age, gender, BMI and baseline values.

Blood pressure and metabolic outcomes

Of the 345 people initially enrolled, 82 were included in the final analysis, with 40 assigned to the intermittent fasting group and 42 to the calorie restriction group. The average age was approximately 36 years, and most participants were women. Demographic characteristics, lifestyle factors, and energy intake were similar in the measured variables, indicating an appropriate balance in the observed characteristics, although unmeasured confounding factors cannot be excluded.

Over 12 weeks, both dietary approaches resulted in significantly lower rates of pressure products, mean arterial pressure and systolic blood pressure. According to the study, systolic blood pressure was significantly lower in the intermittent fasting group compared to the calorie restriction group. Pulse pressure also decreased more in the intermittent fasting group. Within this group, diastolic blood pressure and pulse rate decreased significantly, although these changes were not significantly different between groups.

Triglyceride levels decreased significantly in the 5:2 intermittent fasting group, but the differences between groups were not statistically significant, while total cholesterol, LDL cholesterol, HDL cholesterol, fasting blood glucose and glycosylated hemoglobin remained unchanged in both groups. Liver enzymes improved within the intermittent fasting group, with no differences between groups. No changes were noted in renal function markers.

Changes in cardiovascular risk scores

Both groups experienced significant reductions in BMI-based 30-year Framingham cardiovascular risk scores, with these reductions being greater in the intermittent fasting group. Lipid-based risk scores decreased within the intermittent fasting group but showed no significant differences between groups. Adjusted analyzes confirmed significant differences between groups in pulse pressure, systolic blood pressure, and BMI-based cardiovascular risk.

Interpretation, strengths and limitations

These results are consistent with previous studies reporting the benefits of intermittent fasting on blood pressure, while confirming that short-term interventions may have limited effects on lipid fractions and glycemic markers in predominantly non-diabetic populations. Differences observed between groups were modest in magnitude, and cardiovascular risk results were based on estimated risk scores rather than clinical events. Possible mechanisms include improved autonomic regulation, reduced inflammation, increased fat burning, and metabolic switching during fasting periods, although these pathways have not been measured directly.

Key strengths include registry-based design reflecting everyday clinical practice, comparable baseline characteristics, and use of comprehensive cardiovascular risk scores. Nevertheless, the observational design, short follow-up, modest sample size, missing laboratory values ​​for a significant proportion of participants, and reliance on self-completed dietary data limit causal conclusions. Blinding was not possible, making it difficult to account for all confounding factors.

Overall, the results suggest that intermittent fasting may provide small but potentially meaningful improvements in certain blood pressure measurements and estimated cardiovascular risks, particularly in a relatively young, predominantly female population, necessitating further longer and larger studies to confirm sustainability and clinical impact.

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