TOPLINE:

In patients with obesity, a 3-month dietary intervention with modified alternate-day fasting led to a greater reduction in 24-hour ambulatory blood pressure (BP) compared with other low-calorie diets with different ketogenic potentials, although weight loss and improvement in other anthropometric parameters were achieved with all the diets.

METHODOLOGY:

• Researchers in Spain conducted a subanalysis of a prospective randomised trial in adults with obesity to assess the effect of five weight-loss diets with varying ketogenic potential on BP over 24 hours using ambulatory BP monitoring.
• They included 96 patients with obesity who had BMI between 30 and 45 (mean ages, 45-50 years; 53.33%-82.61% women) from January 2020 to March 2022; all patients had a previous diagnosis of hypertension.
• All patients were randomly assigned to one of five intervention groups with an energy deficit of 600 kcal/d for 3 months:
  • Early time-restricted eating: an eating window between 8 AM and 4 PM
  • Evening time-restricted eating: an eating window between 2 PM and 10 PM
  • Modified alternate-day fasting: alternate between a 24-hour normal calorie diet and a modified 24-hour fast
  • Ketogenic diet: a very low carbohydrate and high-fat diet
  • Control group: a standard Mediterranean diet.
• All patients received dietary counselling from experts, received tailored guidance on general physical fitness, and were encouraged to stay physically active throughout the day with the aim of achieving 10,000 steps daily.
• Assessments at 3 months of intervention included 24-hour ambulatory BP monitoring along with various parameters such as weight, BMI, and body composition.

TAKEAWAY:

• All five diets led to significant reductions in weight, waist circumference, BMI, and fat mass at 3 months. The mean total ketonaemia was highest in the group that received ketogenic diet, lowest in the control group, and intermediate in the other groups (P < .028).
• Patients assigned to modified alternate-day fasting showed the greatest reduction in 24-hour mean BP (-8.14 mm Hg), followed by those assigned to evening time-restricted eating (-3.80 mm Hg), with no significant changes seen in the other groups (between-group P = .026).
• In a separate analysis, only the modified alternate-day fasting group showed a significant reduction of 10.92 mm Hg in 24-hour systolic BP compared with the control group (P < .001).
• Changes in fat mass and baseline 24-hour systolic BP were predictors of changes in 24-hour systolic BP (P < .001 for both), with no influence of age and sex.

IN PRACTICE:

"Not all weight loss strategies seem to result in the same BP improvement. This reinforces the importance of a personalised prescription of weight loss approaches according to each individual BP goal," the researchers reported.

SOURCE:

This study was led by Ana María Gómez-Pérez, Virgen de la Victoria University Hospital, University of Málaga, Málaga, Spain. It was published online on September 05, 2025, in the European Journal of Preventive Cardiology.

LIMITATIONS:

Being a substudy of a trial with some other primary endpoint, the patients were not randomly assigned according to their baseline BP. The lack of a specific tool to assess whether patients adhered to their respective diets limited the interpretation of the results. Additional interactions could not be analysed owing to a small sample size. 

DISCLOSURES:

This study received support from multiple sources, including Instituto de Salud Carlos III and the Junta de Andalucía, with co-funding from FEDER funds. Ketogenic replacement meals in ketogenic diet and modified alternate-day fasting groups were provided by the PronoKal Health Group. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.