The central role of staple foods in weight loss and practical application of "vegetable meals": glycogen balance, carbohydrate energy ratio, and satiety management.

Many modern women, and even some men, try to lose weight by eating less or no staple foods, replacing them with protein-rich foods, vegetables, and fruits. Staple foods typically refer to carbohydrate-rich foods such as rice and noodles. Staple foods are the main source of sugar in the body. The starch in staple foods is broken down in the digestive tract, eventually becoming glucose, which is absorbed into the bloodstream as blood sugar. After eating, the blood glucose level rises rapidly, stimulating insulin secretion, which enters liver cells to synthesize liver glycogen and enters muscle cells to synthesize muscle glycogen.

Glycogen is the body's stored form of glucose. During periods of starvation, blood glucose levels drop, and liver glycogen releases glucose into the bloodstream under the influence of hormones, maintaining a relatively stable blood glucose concentration. Glycogen is an important energy source in the body, providing energy through both aerobic oxidation and anaerobic glycolysis. Some tissues and cells in the body do not store glycogen; for example, brain cells and blood cells must constantly absorb glucose from the blood for energy. Generally, more than 60% of the energy required comes from carbohydrates in food. Therefore, a relatively stable blood glucose concentration is essential for maintaining the physiological functions of vital organs.

Obese patients should appropriately control their food intake to prevent excess energy from being converted into fat. Dieting does not mean not eating, let alone eliminating staple foods. The body needs a sufficient supply of the six major nutrients, especially essential ones. Not eating staple foods not only affects health but also fails to achieve weight loss. During weight loss, it's crucial to rationally control total food intake and maintain a scientifically balanced diet. The recommended intake of carbohydrates for energy in the Chinese Dietary Guidelines should be 55%–65% of total calories, which translates to a daily intake of 200–400g of staple foods.

A vegetable diet refers to a dietary approach that primarily consists of vegetables, completely or almost entirely eliminating grains and meat to reduce total calorie and fat intake. The effectiveness of a vegetable diet for weight loss stems from two main reasons: first, vegetables are low in calories and provide a high feeling of fullness; a single vegetable meal can reduce calorie intake by approximately 300 kcal. Second, vegetables are low in fat, thus reducing overall fat intake. Vegetables also contain abundant fiber, vitamins, and trace elements, which can effectively prevent constipation, a common complication during weight loss.

According to the Chinese Dietary Guidelines, our daily total calorie intake should be balanced with the calories consumed during rest and physical activity. Daily energy intake should at least meet our physiological needs. Obese patients often experience hunger after dietary control due to long-term overeating. Vegetable meals, being bulky, easily create a feeling of fullness after entering the digestive tract, and their low calorie content avoids the possibility of increased calorie intake.

A vegetable meal is generally more suitable for dinner. There are generally two ways to prepare a vegetable meal: one is to use fresh, seasonal vegetables, cooked with minimal oil and salt, and consume no more than 1000g per serving. The other is to use vegetables that can be eaten raw, such as lettuce, tomatoes, and cucumbers, and consume no more than 500g per serving. It is recommended to have a vegetable meal 2-3 times a week. Adding olive oil or similar ingredients to cold vegetable dishes can help supplement essential fatty acids.