How fast should you lose weight? What a safe, lasting rate looks like
This article is general information, not medical advice. It is not a substitute for a doctor, dietitian or other qualified professional who knows your circumstances. If you have a medical condition, are pregnant, or are changing your diet or exercise significantly, talk to one first.
When you want to lose weight, faster always sounds better. But the pace that produces lasting results is steadier than most people expect, and losing weight too quickly brings its own problems. This guide explains the usual recommendation and how to tell whether you are on track, using the trend from the weight tracker.
The recommended rate
Public health bodies including the US CDC and the NHS suggest aiming to lose about 0.5 to 1 kg (1 to 2 lb) a week. A related rule of thumb is roughly 0.5 to 1 per cent of body weight a week, which scales sensibly: someone weighing 120 kg can lose more per week than someone weighing 65 kg. People who lose weight gradually at this pace are more likely to keep it off, because the habits that produce it — moderate portions, regular activity, decent sleep — are ones they can live with. Even modest loss matters for health: losing 5 to 10 per cent of body weight improves blood pressure, blood sugar and cholesterol for many people.
Why the first weeks are faster
Many people lose two or three kilograms in the first week or two, then slow down. Much of that early drop is water, not fat. Eating less carbohydrate reduces the body's glycogen stores, and each gram of glycogen is stored with several grams of water, so emptying them releases water quickly. Less food in the digestive system and less salt add to the effect. It is encouraging but temporary, and the steadier rate afterwards is the real fat loss. Why your weight goes up and down every day explains the water effects in more detail.
The risks of losing too fast
Very rapid loss, more than about 1 to 1.5 kg a week for weeks on end, usually means a very large calorie deficit. That raises the risk of losing muscle along with fat, nutrient shortfalls, fatigue, irritability, hair thinning and gallstones, and it is harder to sustain, so weight often returns. Very low-calorie diets (around 800 kcal a day or less) do have a place, but under medical supervision. A sensible minimum for unsupervised eating is about 1,200 kcal a day for women and 1,500 for men; the calorie calculator flags targets below those. Eating enough protein and doing some resistance exercise help keep muscle while you lose fat.
Why weight loss slows
As you get lighter, you burn fewer calories: a smaller body needs less energy to run and to move. The body also adapts a little to a sustained deficit, and many people unconsciously move less or eat slightly more over time. The result is that the same plan produces slower loss after a few months, and eventually a plateau. That is normal, not failure. Options are to recalculate your needs at your new weight, adjust portions or activity a little, or deliberately hold your weight steady for a while before continuing. How big should your calorie deficit be? shows how the numbers change.
Measuring progress
Because daily weight bounces around, judge your rate over at least two to four weeks. The weight tracker calculates it from a least-squares line through your last four weeks of weigh-ins, which is far steadier than comparing two days, and it warns when the rate is faster than 1 kg a week. Add a goal weight and it estimates when you will reach it at your current pace; treat that as a guide, since the rate will slow. Waist measurements and how clothes fit are good second opinions when the scale stalls. If you are losing weight without trying, or losing it quickly for no clear reason, see a doctor. For a quick view of where you stand, the BMI calculator and the ideal weight calculator are related.
Sources and further reading
The claims in this guide rest on these references, which were checked when the guide was last updated. Spotted an error? The contact page says how to report it.