A Mediterranean Diet and Low-Fat Vegan Diet to Improve Body Weight and Cardiometabolic Risk Factors: A Randomized, Cross-over Trial.
Study Goal
The researchers aimed to compare the relative efficacy of a vegan diet versus a Mediterranean diet in improving body weight and cardiometabolic risk factors in overweight adults.
Results Summary
The vegan diet resulted in significant weight loss (-6.0 kg), improved insulin sensitivity, and reduced LDL and total cholesterol compared to the Mediterranean diet. Blood pressure decreased on both diets, but more so on the Mediterranean diet.
Population
62 overweight adults
Effective Dosage
Not specified
Duration
16 weeks per diet, with a 4-week washout period
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Mediterranean diet | no change | body weight | overweight adults | 0.0 kg | no significant change | #1 |
vegan diet | decrease | body weight | overweight adults | -6.0 kg | decreased | #2 |
vegan diet | decrease | HOMA-IR | overweight adults | - | decreased | #3 |
Mediterranean diet | no change | HOMA-IR | overweight adults | - | no significant change | #4 |
vegan diet | increase | OGIS | overweight adults | +35.8 mL/min/m2 | increased | #5 |
Mediterranean diet | no change | OGIS | overweight adults | - | no significant change | #6 |
vegan diet | no change | PREDIM | overweight adults | - | did not change significantly | #7 |
Mediterranean diet | no change | PREDIM | overweight adults | - | did not change significantly | #8 |
vegan diet | decrease | total cholesterol | participants with no medication changes | 18.7 mg/dL (0.5 mmol/L) | decreased | #9 |
Mediterranean diet | no change | total cholesterol | participants with no medication changes | - | no significant change | #10 |
vegan diet | decrease | LDL-cholesterol | participants with no medication changes | 15.3 mg/dL (0.4 mmol/L) | decreased | #11 |
Mediterranean diet | no change | LDL-cholesterol | participants with no medication changes | - | no significant change | #12 |
Mediterranean diet | decrease | systolic blood pressure | participants with no medication changes | 9.3 mmHg | decreased | #13 |
vegan diet | decrease | systolic blood pressure | participants with no medication changes | 3.4 mmHg | decreased | #14 |
Mediterranean diet | decrease | diastolic blood pressure | participants with no medication changes | 7.3 mmHg | decreased | #15 |
vegan diet | decrease | diastolic blood pressure | participants with no medication changes | 4.1 mmHg | decreased | #16 |
Objective: Evidence suggests that both Mediterranean and vegan diets improve body weight and cardiometabolic risk factors, but their relative efficacy has not been compared in a randomized trial.Methods: In a randomized crossover trial, 62 overweight adults were randomly assigned to a Mediterranean or vegan diet for a 16-week period. Body weight, plasma lipids, blood pressure, and body composition (dual X-ray absorptiometry) were measured. Secondary measures included insulin resistance (Homeostasis Model Assessment, HOMA-IR), oral glucose insulin sensitivity (OGIS), and predicted insulin sensitivity (PREDIM) indices. Thereafter, participants were asked to return to their baseline diets for 4 weeks, after which they began the opposite diet for 16 weeks. The same parameters were measured before and after this 2nd 16-week period.Results: Overall net weight changes were 0.0 (Mediterranean) and -6.0 kg (vegan), (treatment effect -6.0 kg [95% CI -7.5 to -4.5]; p < 0.001). HOMA-IR decreased and OGIS increased on the vegan diet with no significant change on the Mediterranean diet (treatment effect -0.7 [95% CI, -1.8 to +0.4]; p = 0.21; and +35.8 mL/min/m2 [95% CI, +13.2 to +58.3]; p = 0.003, respectively). PREDIM did not change significantly in either group. Among participants with no medication changes, total and LDL-cholesterol decreased 18.7 mg/dL (0.5 mmol/L) and 15.3 mg/dL (0.4 mmol/L), respectively, on the vegan diet, compared with no significant change on the Mediterranean diet (treatment effect -15.6 [-24.6 to -6.6]; p = 0.001 and -14.8 [-23.5 to -6.2]; p = 0.001, respectively); systolic and diastolic blood pressure decreased 9.3 and 7.3 mmHg on the Mediterranean diet, compared with 3.4 and 4.1 mmHg on the vegan diet (treatment effect +5.9 [95% CI +1.0 to +10.9]; p = 0.02; and +1.8 [95% CI -4.6 to +8.1]; p = 0.58, respectively).Conclusions: A low-fat vegan diet improved body weight, lipid concentrations, and insulin sensitivity, both from baseline and compared with a Mediterranean diet. Blood pressure decreased on both diets, more on the Mediterranean diet.Clinical trial registration: ClinicalTrials.gov number, NCT03698955 https://clinicaltrials.gov/ct2/show/NCT03698955?term=NCT03698955&draw=2&rank=1.