How much weight can I lose in a month?

Why the first month reads high

The body holds 400–500 g of glycogen in the muscles and liver, and each gram binds around 3 g of water. When intake falls, that store empties within a few days and the water leaves with it. That accounts for 1.5–2 kg on the scale before any meaningful fat loss.

Three other things move early: less food in the digestive tract, lower salt intake once you eat out less often, and ordinary fluid variation. A 3 kg fall in the first week is common, and around 0.5 kg of it is fat.

By the third week the scale usually stops. This is expected. Fat stores roughly five times more energy per kilogram than the glycogen and water that left first, so the same daily deficit now produces a much smaller change in weight.

This is the point where most people give up. Knowing the pattern in advance is the main protection against it.

What changes your rate of loss

• Starting weight. At the same percentage, a higher starting weight means a larger loss each week.
• Muscle mass. More muscle raises daily energy use, and protecting it during a deficit is what stops progress stalling.
• Age and hormones. Muscle loss and hormonal change alter the picture from the 40s onward. See women's health and men's health for how this differs.
• Sleep and stress. Short sleep raises appetite hormones and makes evening eating harder to resist. Where stress eating is the main pattern, our mental health service covers it.
• Thyroid and blood sugar. Both are checkable, and worth checking before willpower is blamed. A health check-up establishes the baseline.
• Living in Bangkok. Eating out most days, high-sodium food, hot-season fluid shifts, and a commute that removes walking from the day.

Can I lose 10 kg in a month?

For almost everyone the answer is no.

A 10 kg loss in 30 days requires a daily deficit most adults cannot reach without eating too little to be safe. Those who come close usually start from a very high weight, and a large share of the first few kilograms is still water. The cost is muscle loss, a raised risk of gallstones, and the rebound that follows most crash diets.

If a fixed figure by a fixed date has become the goal, say so at the consultation. A four-week deadline is usually workable once the target is rebuilt around what four weeks can deliver.

Why 5–10% is the figure that matters

A loss of 5–10% of body weight is the point at which blood pressure, blood sugar and cholesterol improve measurably. At 90 kg that is 4.5 kg, which is six to ten weeks of steady progress.

It is also the more workable goal. "Lose 20 kg" shows no visible progress for months. "Lose 4.5 kg and repeat the bloods" is finished this quarter.