A Plant-Based High-Carbohydrate, Low-Fat Diet in Overweight Individuals in a 16-Week Randomized Clinical Trial: The Role of Carbohydrates.
Study Goal
The researchers aimed to determine the effects of a low-fat, plant-based diet on body weight, body composition, and insulin resistance.
Results Summary
The study found that a low-fat, plant-based diet significantly reduced weight, fat mass, and insulin resistance, with increased carbohydrate and fiber intake correlating with these beneficial effects.
Population
75 participants randomized into a vegan diet group (n=38) or a control group maintaining their current diet (n=37).
Effective Dosage
Not specified
Duration
16 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
plant-based high-carbohydrate, low-fat (vegan) diet | decrease | Weight | Participants | -6.5 [95% CI -8.9 to -4.1] kg | decreased significantly | #1 |
plant-based high-carbohydrate, low-fat (vegan) diet | decrease | Fat mass | Participants | -4.3 [95% CI -5.4 to -3.2] kg | reduced | #2 |
plant-based high-carbohydrate, low-fat (vegan) diet | decrease | HOMA-IR | Participants | -1.0 [95% CI -1.2 to -0.8] | reduced significantly | #3 |
carbohydrate, as a percentage of energy | decrease | BMI | - | r = -0.53 | correlated negatively | #4 |
carbohydrate, as a percentage of energy | decrease | fat mass | - | r = -0.55 | correlated negatively | #5 |
carbohydrate, as a percentage of energy | decrease | volume of visceral fat | - | r = -0.35 | correlated negatively | #6 |
carbohydrate, as a percentage of energy | decrease | HOMA | - | r = -0.27 | correlated negatively | #7 |
total fiber | decrease | BMI | - | r = -0.43 | correlated negatively | #8 |
insoluble fiber | decrease | BMI | - | r = -0.46 | correlated negatively | #9 |
total fiber | decrease | fat mass | - | r = -0.42 | correlated negatively | #10 |
insoluble fiber | decrease | fat mass | - | r = -0.46 | correlated negatively | #11 |
total fiber | decrease | volume of visceral fat | - | r = -0.29 | correlated negatively | #12 |
insoluble fiber | decrease | volume of visceral fat | - | r = -0.32 | correlated negatively | #13 |
Increased carbohydrate and fiber intake, as part of a plant-based high-carbohydrate, low-fat diet | decrease | weight, body composition, and insulin resistance | - | - | are associated with beneficial effects | #14 |
The effects of carbohydrates on body weight and insulin sensitivity are controversial. In this 16-week randomized clinical trial, we tested the role of a low-fat, plant-based diet on body weight, body composition and insulin resistance. As a part of this trial, we investigated the role of changes in carbohydrate intake on body composition and insulin resistance. Participants (n = 75) were randomized to follow a plant-based high-carbohydrate, low-fat (vegan) diet (n = 38) or to maintain their current diet (n = 37). Dual-energy X-ray absorptiometry was used to measure body composition. Insulin resistance was assessed with the Homeostasis Model Assessment (HOMA-IR) index. A repeated measure ANOVA model was used to test the between-group differences from baseline to 16 weeks. A linear regression model was used to test the relationship between carbohydrate intake, and body composition and insulin resistance. Weight decreased significantly in the vegan group (treatment effect -6.5 [95% CI -8.9 to -4.1] kg; Gxt, p < 0.001). Fat mass was reduced in the vegan group (treatment effect -4.3 [95% CI -5.4 to -3.2] kg; Gxt, p < 0.001). HOMA-IR was reduced significantly in the vegan group (treatment effect -1.0 [95% CI -1.2 to -0.8]; Gxt, p = 0.004). Changes in consumption of carbohydrate, as a percentage of energy, correlated negatively with changes in BMI (r = -0.53, p < 0.001), fat mass (r = -0.55, p < 0.001), volume of visceral fat (r = -0.35, p = 0.006), and HOMA (r = -0.27, p = 0.04). These associations remained significant after adjustment for energy intake. Changes in consumption of total and insoluble fiber correlated negatively with changes in BMI (r = -0.43, p < 0.001; and r = -0.46, p < 0.001, respectively), fat mass (r = -0.42, p < 0.001; and r = -0.46, p < 0.001, respectively), and volume of visceral fat (r = -0.29, p = 0.03; and r = -0.32, p = 0.01, respectively). The associations between total and insoluble fiber and changes in BMI and fat mass remained significant even after adjustment for energy intake. Increased carbohydrate and fiber intake, as part of a plant-based high-carbohydrate, low-fat diet, are associated with beneficial effects on weight, body composition, and insulin resistance.