Goi's Fitness Forum

The Effect of a Plant-Based Low-Carbohydrate ("Eco-Atkins") Diet on Body Weight and Blood Lipid Concentrations in Hyperlipidemic Subjects

Background Low-carbohydrate, high–animal protein diets, which are advocated for weight loss, may not promote the desired reduction in low-density lipoprotein cholesterol (LDL-C) concentration. The effect of exchanging the animal proteins and fats for those of vegetable origin has not been tested. Our objective was to determine the effect on weight loss and LDL-C concentration of a low-carbohydrate diet high in vegetable proteins from gluten, soy, nuts, fruits, vegetables, cereals, and vegetable oils compared with a high-carbohydrate diet based on low-fat dairy and whole grain products.

Methods A total of 47 overweight hyperlipidemic men and women consumed either (1) a low-carbohydrate (26% of total calories), high–vegetable protein (31% from gluten, soy, nuts, fruit, vegetables, and cereals), and vegetable oil (43%) plant-based diet or (2) a high-carbohydrate lacto-ovo vegetarian diet (58% carbohydrate, 16% protein, and 25% fat) for 4 weeks each in a parallel study design. The study food was provided at 60% of calorie requirements.

Results Of the 47 subjects, 44 (94%) (test, n = 22 [92%]; control, n = 22 [96%]) completed the study. Weight loss was similar for both diets (approximately 4.0 kg). However, reductions in LDL-C concentration and total cholesterol–HDL-C and apolipoprotein B–apolipoprotein AI ratios were greater for the low-carbohydrate compared with the high-carbohydrate diet (–8.1% [P = .002], –8.7% [P = .004], and –9.6% [P = .001], respectively). Reductions in systolic and diastolic blood pressure were also seen (–1.9% [P = .052] and –2.4% [P = .02], respectively).

Conclusion A low-carbohydrate plant-based diet has lipid-lowering advantages over a high-carbohydrate, low-fat weight-loss diet in improving heart disease risk factors not seen with conventional low-fat diets with animal products.

Study conclusion

Metabolically controlled diets in which all food was provided were consumed by the participants. The low-carbohydrate diet provided the minimum level of carbohydrates currently recommended (130 g/d) and eliminated common starch-containing foods, such as bread, baked goods, potatoes, and rice. The protein content was provided by gluten (54.8% of total protein), soy (23.0%), fruits and vegetables (8.7%), nuts (7.5%), and cereals (6.0%). Gluten was provided in the nut bread and wheat gluten (also called “seitan”) products and, together with soy, in burgers, veggie bacon, deli slices, and breakfast links. In addition, soy was provided as tofu and soy beverages. Nuts included almonds, cashews, hazelnuts, macadamia, pecans, and pistachios. The fat was provided by nuts (43.6% of total fat), vegetable oils (24.4%), soy products (18.5%), avocado (7.1%), cereals (2.7%), fruits and vegetables (2.3%), and seitan products (1.4%). The diet was designed to provide 26% of calories as carbohydrates, 31% as protein, and 43% as fat. The high-carbohydrate diet was a low-fat lacto-ovo vegetarian diet (58% carbohydrates, 16% protein, and 25% fat) using low-fat or skim milk dairy products and liquid egg whites or egg substitute to ensure a low–saturated fat and low-cholesterol intake. All diets were provided at 60% of estimated calorie requirements using the Harris-Benedict equation with allowance for exercise.

The low-carbohydrate diet featured viscous fiber-containing foods, including oats and barley, for the relatively limited amount of carbohydrates allowed, and the production of a “no starch” high-protein bread made entirely from ground almonds, hazel nuts, and wheat gluten. The carbohydrate foods and low-starch vegetables, emphasizing okra and eggplant, provided 6 to 7 g of viscous fiber per 2000-kcal diet. The bread was provided as part of the diet.

Note: The "low-carb" diet had 130g of carbs, so technically not "low-carb"