In short: the CDC describes a gradual pace of about 1–2 pounds a week2, and the NHS says 0.5–1 kg a week1. Over a month that is roughly 4–8 pounds. The NIDDK suggests an even calmer start: 5–10% of your starting weight over six months3. For someone at 200 pounds, that is about 1.7–3.3 pounds a month. The first month often looks better on the scale, and then the pace slows. That is normal, not a sign that something broke.
To estimate your own maintenance calories and a gentle deficit, use the calorie calculator.
Where 1–2 pounds a week comes from
Both the CDC and the NHS use this range for adults who want to lose weight1,2. It comes from a moderate calorie deficit you can live with: not starving by evening, and not giving up every food you like. How that deficit works is covered in calorie deficit in plain language.
What that means per month at different weights
For people with overweight or obesity, the NIDDK suggests a first goal of 5–10% of starting weight over six months3. We converted that into pounds:
| Starting weight | 5–10% over 6 months | Average per month |
|---|---|---|
| 150 lb | 7.5–15 lb | 1.2–2.5 lb |
| 175 lb | 8.75–17.5 lb | 1.5–2.9 lb |
| 200 lb | 10–20 lb | 1.7–3.3 lb |
| 225 lb | 11.25–22.5 lb | 1.9–3.8 lb |
| 250 lb | 12.5–25 lb | 2.1–4.2 lb |
| 275 lb | 13.75–27.5 lb | 2.3–4.6 lb |
| 300 lb | 15–30 lb | 2.5–5 lb |
That pace is slower than the top of the CDC range, and the two do not contradict each other. The NIDDK figure is a first six-month goal; the CDC figure is a pace that is still considered gradual. If you lost 2–4 pounds this month without going hungry, you are on track.
Why the 3,500-calorie rule overpromises
The popular math goes like this: a pound of fat is about 3,500 calories, so a 500-calorie daily deficit means a pound a week and 52 pounds a year. Real bodies do not follow it.
- Researchers compared the rule with seven experiments in which people’s food was fully controlled or objectively measured. The rule clearly overestimated actual weight loss4.
- In the model by Kevin Hall and colleagues, body weight responds slowly to a change in eating: about half of the eventual change takes around a year5. As weight comes down, the body uses less energy, so the same menu creates a smaller and smaller deficit.
- The same paper found that people with more body fat lose more weight for the same change in intake5. That is why someone at 260 pounds usually moves faster in the first months than someone at 145.
For a more honest projection, try the NIDDK Body Weight Planner6. The Hall paper itself describes a web-based simulator that models weight change over time instead of using a single conversion factor5.
Why the first month is misleading
In the first weeks, weight often drops faster than the deficit explains. Part of the difference is water. Glycogen, the carbohydrate stored in your liver and muscles, is held with about three to four parts water7. When you eat less, some of it is used up, and the water goes with it. Then the pace evens out, and it feels as if everything has stopped. How to tell water from fat, and how not to panic over one morning, is covered in why the scale jumps and weight plateau.
Why faster is not better
- Gallstones. The NIDDK says losing weight very quickly may raise the chance of gallstones: the liver releases extra cholesterol into bile, and the gallbladder may not empty properly. Repeated losing and regaining raises the risk too3.
- Muscle. Some of the weight lost is lean mass, not fat. In a 2026 meta-analysis, lean mass made up about 26% of weight lost in diet-and-activity programs, and about 17.5% where strength training was added8. Protein and strength work help keep muscle: protein and fullness, home workouts for beginners.
- Burnout. The hungrier the plan, the sooner it ends. Why fast-loss promises usually end in regain is covered in why “10 kg in a week” backfires.
How to tell your pace is fine
- Weigh at the same time of day and look at the weekly average, not a single morning.
- Compare month to month. Down 2–8 pounds a month on a moderate deficit is a workable range for most people.
- If the average has not moved for 3–4 weeks, look at portions and drinks before cutting food even harder: counting calories.
- If you are losing noticeably without changing what you eat or how much you move, see a doctor. That is not a win to celebrate.
Common questions
Can you lose 20 pounds in a month?
For most people, no, at least not as fat. Even by the overly optimistic 3,500-calorie rule, it would take a deficit of about 2,300 calories a day, which is more than many people burn in a whole day. A fast drop of that size is mostly water held with glycogen, and it comes back once you eat normally again7.
Why is my friend losing faster than me?
Pace depends on starting weight, height, activity, and how much you eat. At a higher weight, the same deficit produces more pounds lost5. Compare yourself with yourself a month ago, not with someone else’s numbers.
Sources
- NHS: tips to help you lose weight. Aim to lose 0.5–1 kg a week.
- CDC: steps for losing weight. A gradual pace of about 1–2 pounds a week.
- NIDDK: dieting and gallstones. The risk with very fast weight loss, and a first goal of 5–10% over six months.
- Thomas D.M. et al. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? International Journal of Obesity, 2013;37(12):1611–1613.
- Hall K.D. et al. Quantification of the effect of energy imbalance on bodyweight. The Lancet, 2011;378(9793):826–837.
- NIDDK: Body Weight Planner, a calculator that projects weight from food and activity.
- Kreitzman S.N. et al. Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. American Journal of Clinical Nutrition, 1992;56(1 Suppl):292S–293S.
- Eisa and Barood, 2026: share of weight lost as lean mass across weight-loss approaches, meta-analysis.
What readers think
Lean Wisely articles are general reading. See the disclaimer.