In a new study, researchers found that people on a low-fat, plant-based diet ate fewer daily calories but had higher insulin and blood glucose levels, compared to when they ate a low-carbohydrate, animal-based diet.
The findings broaden my understanding of how restricting dietary carbohydrates or fats may impact health.
The research was conducted by a team at the National Institutes of Health.
High-fat foods have been thought to result in excess calorie intake because they have many calories per bite.
Alternatively, high-carb foods can cause large swings in blood glucose and insulin that may increase hunger and lead to overeating.
In the study, the team assigned 20 adults without diabetes for four continuous weeks in the NIH Clinical Center’s Metabolic Clinical Research Unit.
The participants, 11 men and nine women, received either a plant-based, low-fat diet or an animal-based, low-carbohydrate diet for two weeks, immediately followed by two weeks on the alternate diet.
The low-fat diet was high in carbohydrates. The low-carbohydrate diet was high in fats.
Both diets were minimally processed and had equivalent amounts of non-starchy vegetables.
On the low-fat menu, dinner might consist of a baked sweet potato, chickpeas, broccoli and oranges, while a low-carb dinner might be beef stir fry with cauliflower rice.
Participants could eat what and however much they chose of the meals they were given.
The participants were given three meals a day, plus snacks, and could eat as much as desired.
The team showed that people on the low-fat diet ate 550 to 700 fewer calories per day than when they ate the low-carb diet.
Despite the large differences in calorie intake, participants reported no differences in hunger, enjoyment of meals, or fullness between the two diets.
Participants lost weight on both diets, but only the low-fat diet led to a big loss of body fat.
The team also found eating food with an abundance of high glycemic carbohydrates led to big swings in blood glucose and insulin.
But people eating the plant-based, low-fat diet also showed a big reduction in calorie intake and loss of body fat.
This challenges the idea that high-carb diets per se lead people to overeat. On the other hand, the animal-based, low-carb diet did not result in weight gain despite being high in fat.
These findings suggest that the factors that result in overeating and weight gain are more complex than the amount of carbs or fat in one’s diet.
While the low-fat, plant-based diet helps curb appetite, the animal-based, low-carb diet resulted in lower and more steady insulin and glucose levels.
The team says this study brings scientists closer to answering long-sought questions about how what people eat affects their health.
One author of the study is NIDDK Senior Investigator Kevin Hall, Ph.D.
The study is published in Nature Medicine.
Copyright © 2021 Knowridge Science Report. All rights reserved.
