TOPLINE:
In adults with obesity, following a calorie-restricted ketogenic diet, modified alternate-day fasting, or late time-restricted eating led to a greater weight loss than following the Mediterranean diet over 3 months, with the ketogenic diet yielding the best outcomes.
METHODOLOGY:
- Ketone-producing dietary approaches such as the ketogenic diet, time-restricted eating, and modified alternate-day fasting show promise for weight loss, but evidence comparing them to the Mediterranean diet remains limited.
- Researchers conducted a trial to compare the effects of a ketogenic diet (very low-carb and high-fat diet), early and late time-restricted eating (eating windows of 8 AM to 4 PM and 2 PM to 10 PM, respectively), and alternate-day fasting diets (only 4 days per week of normal eating) vs the Mediterranean diet on body composition and cardiometabolic risk factors.
- They randomly assigned 160 adults with obesity (mean age, 45.7 years; mean BMI, 38.4; 70.6% women) to one of five groups: Mediterranean diet (control), ketogenic diet, early time-restricted eating, late time-restricted eating, or modified alternate-day fasting groups.
- All diets were calorie-restricted, with personalized meal plans of 1800 kcal/d for men and 1400 kcal/d for women, aiming for an energy deficit of 600 kcal/d on the basis of estimated energy requirements.
- The primary outcome was differences in weight loss from baseline to 3 months between the Mediterranean diet group and each intervention group.
TAKEAWAY:
- At 3 months, the greatest difference in weight loss was between the control and ketogenic diet groups (mean difference [MD], -3.78 kg; 95% CI, -5.65 to -1.91 kg), followed by the difference between the control and modified alternate-day fasting groups (MD, -3.14 kg; 95% CI, -4.98 to -1.30 kg).
- Similarly, compared with the control group, the late time-restricted eating group showed a significant weight-loss difference (MD, -2.27 kg; 95% CI, -4.13 to -0.40 kg) at 3 months, but the early time-restricted eating group didn’t.
- Greater reductions in body fat mass were observed in the early time-restricted eating and modified alternate-day fasting groups compared with the control group.
- No significant differences in fasting glucose levels, lipid profiles, or blood pressure were found between the control and intervention groups at 3 months.
IN PRACTICE:
“A calorie-restricted KD [ketogenic diet], mADF [modified alternate day fasting], or lTRE [late time-restricted eating] may be more effective than a calorie-restricted MedDiet [Mediterranean diet] in terms of weight loss in patients with obesity,” the authors of the study wrote.
SOURCE:
This study was led by José Ignacio Martínez-Montoro and Borja Bandera, Virgen de la Victoria University Hospital, Málaga, Spain. It was published online in BMC Medicine.
LIMITATIONS:
This study assessed body weight and cardiometabolic outcomes only over a short 3-month period, and different findings might have been observed with longer follow-up. Body composition was measured using bioelectrical impedance analysis, which is less precise than dual x-ray absorptiometry. Additionally, the findings cannot be generalized to other populations, including patients with diabetes and people from other races or ethnicities.
DISCLOSURES:
This study received grant support from Instituto de Salud Carlos III. Some authors reported receiving research support from various sources. None of the authors disclosed any competing interest.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.