How does insulin affect weight loss? Understanding obesity hormones and weight management.

Insulin is a hormone responsible for regulating blood sugar levels and is also the hormone that controls the body's fat storage. When we consume sugary foods, the sugar in the food is broken down by various enzymes and eventually absorbed by the small intestine, converting it into glucose, which is then transported throughout the body via the bloodstream.

When blood glucose levels rise, the pancreas begins to work. The pancreas secretes insulin, which promotes the transfer of glucose from the blood into the cells, helping to regulate blood sugar and maintain blood glucose levels within a safe range. After being converted into glycogen, the glucose is primarily stored in the liver and muscles, but the storage capacity for glycogen in the liver and muscles is very limited. A normal person can only store about 100 grams of glycogen in the liver; and for muscle glycogen, if you don't engage in much physical activity or exercise, the amount you can store is even less.

The remaining large amount of glycogen enters fat cells, is converted into fat, and stored in the body, leading to obesity. This is why insulin is called the "obesity hormone." Therefore, the more sugary foods you eat, the more fat your body will convert and store, resulting in unwanted "love handles," "beer belly," and "elephant legs."

Excessively high insulin levels also inhibit the secretion of glucagon, which helps with fat loss, and growth hormone, which helps with muscle growth.

At the same time, high insulin levels also promote the kidneys' absorption of sodium, causing more sodium to be retained in the body, leading to edema. In addition, the excess glycogen itself increases water retention; 1 gram of glycogen can carry about 3 grams of water, further increasing the likelihood of edema. Edema makes the body look fatter than it actually is.

Insulin is a storage hormone; the more insulin is released, the easier it is for the body to accumulate fat. If you frequently consume high-sugar foods, a vicious cycle begins. Because cells have a limited capacity to receive glucose, if blood insulin levels remain high for a long time, the cells' sensitivity to insulin decreases, leading to insulin resistance. Just as people who frequently get sick and receive antibiotic injections develop antibiotic resistance, leading to the same dose of medication being ineffective in treating the original illness and requiring increased dosages, people with insulin resistance experience a similar phenomenon. The same dose of insulin is unable to move the glucose from the bloodstream into the cells, so the pancreas needs to secrete more insulin to lower blood sugar. Over time, this creates a vicious cycle, and the body's cells become increasingly resistant to insulin. Since insulin is a hormone that promotes fat synthesis, this large amount of insulin causes the body to synthesize more fat, making insulin resistance one of the main reasons for the increasing obesity in modern people.

Insulin resistance most easily leads to abdominal fat accumulation. If your waist-to-hip ratio is greater than 0.9, there is a greater likelihood of significant insulin resistance. For example, abdominal obesity is a typical symptom of insulin resistance. Two people with different degrees of insulin resistance will experience significant differences in weight loss results. People with milder insulin resistance lose weight faster, while those with more severe insulin resistance lose weight more slowly.

Insulin resistance also hinders the brain's reception of leptin signals, further leading to leptin resistance. Leptin controls the body's satiety signals; once leptin resistance occurs, the brain will not receive the "stop eating when full" signal. As a result, we are more likely to experience increased appetite, leading to a situation where we don't stop eating until we feel uncomfortably full.

In addition to causing obesity, insulin resistance can also trigger chronic diseases such as diabetes, heart disease, high blood pressure, gout, and metabolic syndrome.