Deficitly
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In a calorie deficit but not losing weight?
If you're eating less but the scale won't move, it's rarely a broken metabolism. The usual reasons are water retention hiding fat loss, eating more than you think (most people undercount by 10–30%), and a maintenance that's lower than you assumed, especially after losing weight. Give it 3–4 weeks of steady eating and look at the trend; if it's still flat, work out your real TDEE from your own numbers below and adjust by 100–200 calories.
1. Water is hiding the fat loss
Your weight can swing 1–2 kg (2–4 lb) from one day to the next with water, salt, carbs, food in your gut and, for women, the menstrual cycle. Starting a new exercise routine also makes muscles hold water for a while. Fat loss of 0.3–0.5 kg a week easily disappears under that noise for a week or two. Weigh yourself several times a week at the same time of day and compare weekly averages, or compare the same point in your cycle. More in why your weight fluctuates.
2. You're eating more than you count
Studies regularly find people underestimate what they eat by 10–30%. The usual culprits: cooking oil and butter, drinks, sauces, bites while cooking, and portions estimated by eye. A tablespoon of oil is about 120 calories. Weighing food for a couple of weeks usually finds the gap.
3. Your maintenance is lower than you think
Every calculator is an estimate, usually within about 10%, so your real maintenance could be 200 calories below the number you planned with. It also drops as you lose weight: a lighter body burns less at rest and on every step.
| Weight | Woman165 cm | Man178 cm |
|---|---|---|
| 100 kg 220 lb | 2,340 | 2,670 |
| 90 kg 198 lb | 2,190 | 2,520 |
| 80 kg 176 lb | 2,040 | 2,360 |
| 70 kg 154 lb | 1,890 | 2,210 |
| 60 kg 132 lb | 1,730 | 2,050 |
Losing 10 kg lowers maintenance by about 150 calories a day for the woman above: half of a typical deficit. Recalculate every few kilos in the maintenance calorie calculator. If you were losing and then stopped, see weight-loss plateau.
4. It hasn't been long enough
With a deficit of 0.5% of your weight a week, the real loss is a few hundred grams a week: less than daily water swings. Judge progress after 3–4 weeks, not 3–4 days. More on what to expect from a 500-calorie deficit.
5. Exercise calories are counted twice
Fitness watches tend to overestimate calories, and many count the calories you'd burn anyway. If you eat back what your watch says on top of a target that already includes your activity, the deficit shrinks or disappears. See should you eat back exercise calories?
6. Weekends undo the weekdays
A deficit of 500 a day from Monday to Friday is 2,500 calories. Two weekend days at 1,000 over maintenance take back 2,000 of it, leaving 500 for the whole week: about 0.06 kg. It's the weekly total that counts.
7. A medical reason (less common)
An underactive thyroid, PCOS, and some medicines (including certain antidepressants, steroids and insulin) can make losing weight harder, though a deficit still works. If you've ruled out the above and nothing changes for 2–3 months, or you have other symptoms, talk to your doctor.
What to do next
- Keep your intake steady for 3–4 weeks and track it honestly.
- Weigh several times a week and compare weekly averages.
- Work out your real TDEE from your results with the box above.
- Set a new target 300–500 below it in the calorie deficit calculator, never below 1,200 (women) or 1,500 (men).
Why calculator numbers and real results differ is covered in how accurate TDEE calculators are.