There’s a new entry in the ongoing dispute between low-carb and low-fat diets. In the study, researchers recruited 164 overweight or obese individuals (American Journal of Clinical Nutrition, Sept. 27, 2021). They assigned these people randomly to one of three diets that they followed for five months. The diets were designed so that people neither gained nor lost weight during that time. Before the study began, however, each participant had lost approximately 10 percent of their body weight over 10 weeks.
Diets Were Low-Carb, Medium-Carb and High-Carb:
All three diets got 20 percent of their calories from protein, but they ranged from low-carb (20 percent carbohydrate) to high-carb (60 percent carbohydrate). Some individuals ate a diet deriving 40 percent of its calories from carbohydrates. The investigators didn’t want to rely on people following dietary instructions. Instead, they provided each volunteer with prepared meals that met the exact requirements of the study.
Many dieters are enthusiastic about low-carb diets because they see a rapid response on the scales. However, doctors (especially cardiologists) worry that a low-carb diet, which is necessarily high in fat, would raise blood lipids. If it did, it might increase their risk for cardiovascular complications. Each of the study diets got 35 percent of its fat from saturated fat. As a result, people on the low-carb diet consumed significantly more saturated fat. Did it raise their cholesterol?
Metabolic Response to the Diets:
The scientists found that people on the low-carb diet had no change in LDL cholesterol compared to those in the high-carb group. However, they had healthier blood fat profiles and lower insulin resistance. In addition, their Lp(a) dropped by 15 percent. Lipoprotein (a) is an independent risk factor for cardiovascular disease.
The authors offer this summary:
“These findings suggests that a dietary strategy focused on carbohydrate restriction might not raise, and could potentially lower, CVD risk. To the extent that a low-carbohydrate diet results in greater weight loss, overall magnitude of CVD risk reduction could be greater than suggested here.”
Can You Follow This Diet?
If you wanted to try this at home, you probably could get close. The low-carb diet eliminated processed foods and sweets but included fruits and nonstarchy vegetables. Most of the fat in the diet came from olive oil, avocados or nuts. You can learn more about cooking meals with these characteristics in our book, Recipes & Remedies From The People’s Pharmacy.