Struggling to lose weight?
Write down one normal day first. In a small study, people who said they ate under 1,200 calories left out almost half of what they ate. But three health conditions can make it harder too.
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Why am I struggling to lose weight?
It may be food and drink you haven’t counted. In a 1992 study, 10 people said they couldn’t lose weight on under 1,200 calories a day. Researchers measured what they really ate for 14 days.
On average, they had under-reported their food by 47%. They also thought they moved about half as much again as they did.
Source: Lichtman, NEJM 1992
Their bodies were not slow. The energy they burned was within 5% of what was expected for their size.
It was a small study of people living with obesity, so it can’t speak for everyone. But it’s a free thing to rule out first. The NHS starts in the same place: count the food and drink you have on a typical day.
I can’t lose weight: what should I check first?
Check the easy things to miss. Portions are a big one. The NHS gives rice as an example: a 75g portion is 260 calories, but 150g is 520.
What to check before you change your diet
- Write down everything you eat and drink on one normal day.
- Count alcohol, fizzy drinks and juices, the oil and spreads you cook with, toppings like cheese, and sauces like mayo and ketchup.
- Weigh food before you cook it while you learn your portions.
- Cut around 600 calories a day from your total.
- Look at your sleep. Poor sleep may make you choose high-calorie foods, or feel too tired to exercise or cook.
- Weigh yourself regularly. Aim to lose 0.5 to 1 kg a week.
Sources: NHS Better Health; NHS Better Health: lose weight; NHS
The NHS says alcohol is high in calories. Swaps are in the lowest calorie alcoholic drinks. For how to count, see how many calories to lose weight.
Why am I not losing weight any more?
Some slowing is normal. In one computer model, weight came off slowly on the same diet. It took about a year to lose half of what that diet would ever take off.
So slower loss is expected over time. Count a normal day again and check your 600-calorie cut is still there. The NHS says losing weight is not easy and takes time.
Short sleep may matter too. In a small trial, 10 overweight adults ate the same cut diet for 14 days, once with 8.5 hours in bed and once with 5.5.
Source: Nedeltcheva, Ann Intern Med 2010
Only 10 people took part, so treat it as a clue. If you sleep badly, the NHS says that can make it harder to lose weight. To set a fair pace, see how much weight you can lose in a month.
Could a health condition or medicine be the reason?
Sometimes. The NHS gives three examples of health conditions that cause weight gain: an underactive thyroid, PCOS and Cushing’s syndrome.
A GP can test for them. Depression, other mental health conditions and your genes can make it harder too.
| Condition | Other signs the NHS lists | Tests the NHS describes |
|---|---|---|
| Underactive thyroid | Feeling very tired or cold, constipation, dry skin or hair | Blood test for TSH and T4 (thyroid hormones) |
| PCOS, a hormone condition that affects the ovaries (the NHS now calls it PMOS) | Irregular periods, extra hair growth, oily skin and acne | Blood tests for hormones and insulin resistance, and a scan if over 18 |
| Cushing’s syndrome (too much of the stress hormone cortisol) | More fat on the tummy, neck and upper back, thin arms and legs, a red round face | Cortisol in your blood, pee or spit |
Sources: NHS: underactive thyroid; NHS: PMOS; NHS: Cushing’s
Insulin resistance means your body doesn’t respond well to insulin, the hormone that controls blood sugar. See the insulin resistance blood test.
More detail is in underactive thyroid symptoms and the PCOS blood test guide.
Some medicines can make it harder too. The NHS lists some steroids, antidepressants and beta blockers.
Never stop or change a prescribed medicine without your prescriber. Being over 55, or going through the menopause, can also make it harder. See menopause weight gain, and the weight loss blood test guide for other markers.
When to speak to a GP
Book an appointment if:
- Your BMI (your weight compared with your height) is overweight or obese and you want help to lose weight, your waist is more than half your height, or obesity runs in your family.
- Your BMI is overweight or obese and you have pre-diabetes, diabetes, high blood pressure, joint pain, high cholesterol, sleep apnoea (breathing that stops and starts as you sleep) or heart and blood vessel disease.
- You think you might have an underactive thyroid or PCOS, or PCOS symptoms affect your everyday life.
- You have signs of Cushing’s syndrome, especially if you take steroid medicine.
- You have, or think you may have, an eating disorder, such as binge eating.
A GP can refer you to weight management programmes, medicines or surgery. Compare them in weight loss programmes.