**Low-fat foods are often considered ideal for a healthy diet due to their ability to reduce fat intake. However, should low-fat be equated with a healthier diet? First of all, it is crucial to understand the concept of low-fat foods. These foods aim to reduce the amount of fat in the diet by reducing the original fat or using fat substitutes to reduce the total amount of fat in the diet. In certain cases, choosing low-fat foods can indeed help reduce the risk of certain health problems, and you can achieve your goal of eating a healthy diet by adjusting your fat intake.
Many people see the "light" label on the food packaging and mistakenly think that it means that it can be eaten without restrictions. However, foods that are advertised as "light" or "low-fat" do not equate to being low in calories. According to the country's food labeling regulations, "low-fat" means that there is no more than 3 grams of fat per 100 grams of food, and "low calorie" means that there are less than 40 calories per 100 grams of food. For example, many "low-fat" yogurts are low in fat, but their high sugar content may be equivalent to the calories of five and a half sugars, far exceeding the common belief that "low fat equals low calories". In addition, "light" sometimes refers only to a food that has a light taste, light color, or soft texture, and does not mean that it is low in fat or calories. Consumers should read food labels carefully to avoid falling into the "trap" of misleading marketing.
In a study conducted at the National Institutes of Health's Clinical Research Center for Metabolism, a total of 20 non-diabetic** participants, including 11 men and 9 women. The study was designed so that participants first followed two different diet plans, a low-fat diet rich in plant-based ingredients and a low-carb diet dominated by animal foods, each for two weeks, and then immediately switched to another diet plan with alternating diets for two weeks. In a low-fat diet, the proportion of carbohydrates is higher, while in a low-carbohydrate diet, the fat content is higher. Specifically, a plant-based, low-fat diet accounts for 10% of total energy3%, carbohydrates account for 752%；In the animal-based low-carb diet, fat accounts for 758%, carbohydrates only 10%. Both diets reduce the proportion of processed foods as much as possible and guarantee the same intake of non-starchy vegetables. During the study period, participants were provided with three meals and snacks per day by the research team, and the amount of food was determined by the participants.
It was found that participants who followed a low-fat diet consumed 550 to 700 fewer calories per day compared to a low-carb diet. Despite significant differences in calorie intake, participants reported no significant differences in hunger, enjoyment of food, or satiety between the two diets. Both diets promoted weight loss, but low-fat diets were more effective at reducing body fat. This finding challenges the common notion that a high-carbohydrate diet can lead to overeating, and that even high-carbohydrate intake does not necessarily cause drastic fluctuations in blood sugar and insulin levels. In contrast, animal-based low-carbohydrate diets were high in fat but did not show weight gain.
Study leader Hall noted that both dietary strategies have their benefits in the short term, with a low-fat diet helping to control appetite and an animal-based low-carbohydrate diet helping to maintain low and stable levels of insulin and glucose. However, it is unclear whether the health effects of these diets are long-lasting. This study provides insight into the impact of both dietary approaches, providing a scientific basis for developing a personalized diet plan.