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, according to a small but highly controlled study 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.

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.

Examples of dinners given to study participants: low-carb, animal-based diet (left) and low-fat, plant-based diet (right).

The main results 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 eating food with an abundance of high glycemic carbohydrates that resulted in pronounced swings in blood glucose and insulin, people eating the plant-based, low-fat diet showed a significant reduction in calorie intake and loss of body fat, which 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,” said Hall.

The plant-based, low-fat diet contained 10.3% fat and 75.2% carbohydrate, while the animal-based, low-carb diet was 10% carbohydrate and 75.8% fat.

Both diets contained about 14% protein and were matched for total calories presented to the subjects, although the low-carb diet had twice as many calories per gram of food than the low-fat 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,” Hall said.

Reference: “Effect of a plant-based, low-fat diet versus an animal-based, ketogenic diet on ad libitum energy intake” by Kevin D.

January 19, 2021

January 19, 2021

January 19, 2021

January 19, 2021