Dieting, including intermittent fasting, fundamentally aims to reduce calorie intake, helping the body burn excess fat for weight loss. However, dieting alone does not guarantee sustainable weight loss. You might be gaining weight due to common mistakes, such as: excessive calorie restriction (which slows metabolism and causes muscle loss), fasting (stimulating cravings and compensatory eating), insufficient protein, dehydration, or consuming "zero calorie" foods with hidden sugars. Unsustainable, restrictive diets often lead to a rapid regain of lost weight.

If calorie intake is drastically and abruptly cut, the body slows its metabolism to conserve energy. It also breaks down muscle for energy, further slowing calorie burning and making fat gain easier. Skipping meals or prolonged fasting stimulates the production of the hunger hormone ghrelin, increasing appetite and prompting compensatory eating at subsequent meals. Skipping breakfast while dieting raises the risk of metabolic disorders and protein deficiency. Protein boosts metabolism and satiety, so a lack of it slows this process and increases cravings.

Eating whole-grain bread, bananas, and peanut butter for sustained fullness. AI-generated image.

Many athletes consume a lot of protein to build muscle; however, protein from calorie-dense sources like red meat and processed meats can lead to excess energy intake. When calorie intake exceeds calorie expenditure, the body stores the surplus energy as fat, leading to weight gain. Dieting without adequate water intake also slows fat burning, hindering weight loss effectiveness.

You should consult a weight management or nutrition specialist for advice on a scientific, sustainable weight loss approach. Focus on reducing calorie intake to a level equal to or lower than your calorie expenditure. Ensure your meals are balanced with essential nutrients like carbohydrates, fiber, and protein, and drink sufficient water. Overweight or obese individuals should aim to reduce daily calories by 300-500, losing 2-4 kg per month or 5-10% of their body weight over 3-6 months to maintain health and ensure safety.

Doctor Vo Tran Nhu Thao

Endocrinology - Diabetes Department

Tam Anh General Hospital Ho Chi Minh City