Body biology fights against excessive calorie reduction
When calorie intake drops sharply, the body tends to consider it a sign of energy deficiency. This triggers a series of hormonal changes to protect energy sources.
Ms. Prachi Mandholia - clinical nutritionist in Mumbai, India, said that when eating too little, leptin levels, the hormone that creates a feeling of fullness, will decrease, while ghrelin, the hormone that stimulates hunger, will increase. At the same time, the metabolic rate during rest also slows down.
The body will try to save energy. People who diet excessively often feel tired, cold, irritable and always hungry. This is a natural biological reaction, not due to lack of will," Ms. Mandholia explained.
Not only that, nutrition studies show that not all calories have the same effect. A meal of pure foods rich in fiber and protein can help feel full longer, stabilize blood sugar and reduce cravings.
Conversely, processed foods, even with equivalent calories, are often absorbed quickly, causing blood sugar to spike suddenly and then drop sharply, thereby stimulating hunger to return.
According to Dr. Walter Willett - professor of nutrition epidemiology at Harvard T.H.Chan School of Public Health, food quality plays a decisive role in long-term weight control.
"A diet rich in whole foods such as vegetables, fruits, whole grains and high-quality protein can help the body regulate calories more effectively," he said.
Hormones, sleep and stress also determine weight
In addition to nutrition, many other factors also affect weight loss ability such as sleep, stress, and endocrine health.
Prolonged stress increases the hormone cortisol, a factor that promotes fat accumulation, especially in the abdomen. Lack of sleep also causes the body to increase cravings and reduce the ability to recognize fullness signals.
Some health conditions such as thyroid disorders or polycystic ovary syndrome can also make weight loss more difficult, even after cutting calories.
Experts believe that instead of focusing entirely on the number per kilogram, people should prioritize improving health indicators such as energy, sleep quality, waist circumference, blood sugar or cholesterol.
When the goal shifts from "losing weight" to "improving overall health", weight loss often becomes a natural consequence.
According to nutrition experts, a sustainable weight loss strategy needs to be based on long-term habits such as a balanced diet rich in protein and fiber, maintaining stable meal times, getting enough sleep, managing stress and exercising regularly.
Long-term weight loss is not about eating as little as possible, but about eating smartly, respecting the body and building a healthy lifestyle. Calorie reduction may be the starting point, but the real foundation of sustainable weight loss is adequate nutrition, not deprivation.
