Limitations of Food-Assisted Weight Loss and Risks of Low-Carb Diets: An Analysis of the Capsaicin Effect and the Advantages and Disadvantages of Carb Restriction

The chili pepper diet, as the name suggests, aims to achieve weight loss by eating chili peppers. The core of this diet lies in capsaicin, a substance abundant in chili peppers. Scientific research has found that this substance can produce weight-loss effects through multiple mechanisms. Capsaicin can activate the TRPV1 signaling pathway, inhibit fatty acid synthesis, promote energy expenditure, and reduce lipid accumulation, significantly reducing the weight of diet-induced obese mice. Capsaicin can also enhance sympathetic nerve activity, thereby suppressing appetite and increasing energy metabolism. Japanese researchers have verified in human trials the inhibitory effect of eating chili peppers for breakfast on the intake of carbohydrates, fats, and proteins. Furthermore, human trials have confirmed that capsaicin can significantly reduce postprandial blood glucose, insulin, and C-peptide levels, and improve insulin resistance. Although basic research suggests the potential weight-loss benefits of capsaicin, high-quality human studies have shown that its weight-loss effect is not ideal. Consuming chili peppers/capsaicin can increase the average daily energy expenditure of overweight and obese individuals by 58 kcal, which is only about 1/30th of the total daily energy intake of an average person, indicating that relying solely on chili peppers for weight loss is far from sufficient. Currently, there is a lack of research on the long-term effects of consuming chili peppers for weight loss. Whether the body will develop tolerance after long-term consumption of chili peppers, leading to a decrease in weight loss effectiveness, is also unknown. Increased capsaicin intake can also cause various health problems. In animal experiments, high doses of capsaicin can cause the death of some neurons in experimental rats. Large amounts of capsaicin can also cause symptoms such as congestion, edema, and spasms in the gastrointestinal mucosa of experimental animals. Discomfort symptoms after consuming foods high in chili peppers, such as hot pot, are also common, mainly including dry mouth, oral ulcers, sore throat, diarrhea, abdominal pain, and burning sensation in the anus. A survey in Mexico showed that people who eat chili peppers are many times more likely to develop gastrointestinal cancer than those who don't. Whether it's hot pot or other forms of chili pepper seasoning, a large amount of oil is usually added during processing. For those trying to lose weight, consuming processed chili peppers also increases oil intake. Therefore, chili peppers should only be used as a supplementary food in the weight loss process; relying entirely on chili peppers for weight loss is unrealistic. The claim that "eating more fat and meat and not eating grains can easily achieve a perfect figure" is essentially a typical low-carbohydrate weight loss diet. A low-carbohydrate diet (LCD) restricts carbohydrate intake and replaces it with foods rich in protein and/or fats, as well as other low-carbohydrate foods. Based on intake levels, it can be categorized into low-carbohydrate diets (20%–40%), limited-carbohydrate diets (10%–20%), and very low-carbohydrate diets (5%–10%). Currently popular low-carbohydrate diets include: Paleo diet, Atkins diet, ketogenic diet, low-carbohydrate Mediterranean diet, low-carbohydrate high-protein diet, and zero-carbohydrate diet. Carbohydrates are the fastest-growing energy source among the three macronutrients. People who try to lose weight on a low-carbohydrate diet often believe that simply eliminating or reducing staple foods will reduce fat synthesis. However, research shows that excessive dietary energy intake and insufficient energy expenditure are the main causes of increased fat synthesis and obesity. Simply restricting carbohydrates without restricting total energy intake or increasing energy expenditure will not achieve effective weight loss. The body's energy metabolism relies on the daily dynamic synthesis of glycogen. Small-sample studies suggest that long-term low-carbohydrate diets can reduce weight by mobilizing fat for energy, reducing insulin secretion, or suppressing appetite. However, in reality, low-carbohydrate diets are not more effective for weight loss than restricting energy and fat intake. Furthermore, long-term replacement of carbohydrates with high-protein, high-fat diets pose significant health risks. Prolonged consumption of fat for energy leads to the production of large amounts of ketones, which can cause ketoacidosis (ketoacidosis). Mild cases may present with nausea and vomiting, while severe cases can result in dehydration and shock. Long-term high protein intake also increases calcium loss, purine intake, and the burden on the liver and kidneys, increasing the risk of gout, osteoporosis, and kidney stones. From a carbohydrate perspective, a long-term lack of carbohydrates in the body leads to a drop in blood sugar levels, causing dizziness, blurred vision, cold sweats, and fatigue. Glucose is the only energy source the brain can utilize; a long-term deficiency can damage the brain, causing memory loss. Severe hypoglycemia can even damage brain cells, leading to irreversible brain damage. Simultaneously, a monotonous diet significantly reduces the intake of certain vitamins, dietary fiber, and trace elements, easily causing constipation, gut microbiota imbalance, and malnutrition. Scientific dietary management is crucial for healthy weight loss. Choosing the right staple foods not only increases satiety and reduces food intake, but also activates key enzymes in metabolism, increases dietary fiber, and maintains nutritional balance. Recommendation:

Limit total energy intake and increase physical activity;

A diverse diet with a focus on beans and whole grains, and moderate intake of tubers;

Avoid refined pastries, breads, fried foods, and other foods that are high in oil, sugar, and energy density;

Eat a light diet, low in salt and oil, and choose appropriate cooking methods;

Eat more vegetables and a moderate amount of fruit;

Changing the order of meals, to soup, vegetables, meat, and staple food in that order, can help reduce food intake.

Eat slowly and mindfully.