Why am I not losing weight?

1. You are eating more than you think

This is the most common reason by a long way. In a well-known study published in the New England Journal of Medicine, people who said they could not lose weight on low calories under-reported what they ate by almost half and over-reported their exercise by about the same amount. Nobody was lying; it is just hard to remember and estimate food.

The usual culprits are cooking oil and butter, milk in tea and coffee, drinks, bites while cooking, and leftovers from the children's plates. A tablespoon of oil is 120 kcal; three lattes a day can be 400.

2. Weekends undo the week

A 500 kcal deficit from Monday to Friday is 2,500 kcal. A Saturday with a takeaway and a few drinks can easily be 2,000 kcal over, and Sunday brunch does the rest. Look at your total for the whole week. See calories in alcohol and calories in British food for typical numbers.

3. Water retention is hiding fat loss

Your weight can swing by 1 to 2 kg from one day to the next with salt, carbohydrate, hormones, poor sleep or a new exercise routine. Fat loss of 0.5 kg a week is easily hidden under that. Weigh yourself at the same time each morning and compare weekly averages instead of single days.

4. Your target is based on your old weight

As you lose weight, you burn fewer calories. After losing a stone, your maintenance calories may be 100 to 200 kcal lower than when you started, so the same intake gives a smaller deficit. Recalculate with our calorie calculator at your current weight.

5. You are eating back exercise calories

Fitness trackers and gym machines often overestimate calories burned. If you add those calories to your food budget, the deficit can disappear. Read how accurate Apple Watch calories are.

6. You are moving less without noticing

When people eat less, they often move less during the rest of the day: fewer steps, more sitting, less fidgeting. That can cancel out a few hundred calories. Keeping an eye on your daily step count helps; use the steps calculator to see what your steps are worth.

7. You started lifting weights

New strength training causes muscles to hold extra water for repair, which can mask fat loss for two or three weeks. Your waist measurement is a better guide during this time. If your waist is shrinking, it is working. See body recomposition.

8. Sleep and stress

Short sleep increases hunger and cravings and makes it harder to stick to a plan. High stress can increase water retention. Neither stops fat loss on its own, but both make the deficit harder to keep.

9. A medical reason

An underactive thyroid, polycystic ovary syndrome (PCOS), menopause and some medicines, including steroids and some antidepressants, can make weight loss harder. If you have tracked carefully for several weeks with no change, speak to your GP.

How to break a plateau

1. Track everything you eat and drink for two weeks, including oil, sauces and drinks.
2. Weigh food you eat often, such as cereal, pasta, cheese and nuts, at least once.
3. Recalculate your calorie target at your current weight.
4. Compare weekly average weights and waist measurements, not single readings.
5. If nothing has changed after three weeks, cut 100 to 200 kcal or add 2,000 steps a day.
6. Keep protein high so you hold on to muscle.

Tracking every meal is the step people skip, because it takes time. With Calori you take a photo of your plate and the calories and macros are logged for you, which makes two careful weeks much easier to get through.