Why am I not losing weight? 7 honest reasons (and what to do)

You've cut back. You skip the second plate, you said no to dessert, maybe you're even training. And the scale still says the same number it said three weeks ago.

That is one of the most frustrating feelings in fitness, and it is extremely common. The good news: there is almost always a normal, fixable reason. Here are the seven big ones.

1. You're eating more than you think

This is the number one reason, and it isn't about willpower. Humans are just bad at estimating food. In a well-known study in the New England Journal of Medicine, people who said they couldn't lose weight on a low-calorie diet were actually under-reporting what they ate by 47% and over-reporting their exercise by 51%. They weren't lying. They simply didn't notice the extras.

The extras are things like the handful of nuts while cooking, the bites of your kid's food, the "small" snack at work, and a portion that slowly grew bigger over a few weeks.

Fix: track everything you eat for two weeks, honestly, including the small stuff. You don't have to do it forever. Two weeks is usually enough to find the leak.

2. Cooking oil and drinks don't feel like food

Oil is the most calorie-dense thing in most kitchens. One tablespoon of cooking oil is about 120 calories. A pan of stew, fried eggs or fried plantain can easily soak up two or three tablespoons per plate. That's 240 to 360 calories you never "ate" in your head.

Drinks are the same. A regular 330 ml can of cola is around 140 calories. Juice, sweet tea, malt drinks, beer and fancy coffees add up fast, and they don't fill you up the way food does.

Fix: measure the oil you cook with for a week, and count every drink that isn't water, black coffee or plain tea.

3. Your weekends cancel out your weekdays

Here is some simple maths. Say you eat 500 calories under your needs every day from Monday to Friday. That's a 2,500 calorie deficit. Then on Saturday and Sunday you eat 1,250 calories over each day: a night out, a party plate, brunch. You're back to zero for the week.

You "dieted" five days out of seven and lost nothing. It feels unfair, but it's just addition.

Fix: look at your weekly total, not just your daily one. You can still enjoy the weekend; just plan for it.

4. Water weight is hiding your fat loss

Your body weight can move up or down by one to two kilograms from one day to the next without any change in fat. Salt, carbs, hormones, how much water you drank, a hard workout and even when you last went to the toilet all change the number.

Carbs matter a lot here: your body stores carbohydrate in your muscles and liver together with water, roughly three grams of water for every gram of stored carbohydrate. So a heavy rice or pasta dinner can show up as a "gain" the next morning that is really just water.

Fix: weigh yourself at the same time each morning, after the toilet and before eating, and look at your weekly average. If the average is dropping, you are losing fat, even if Tuesday was higher than Monday.

5. Your expectations are too fast

A healthy, sustainable pace for most people is about 0.5% to 1% of body weight per week. For someone who weighs 80 kg, that is 0.4 to 0.8 kg a week. Some weeks will be less, a few will be more.

The old rule that "3,500 calories equals one pound of fat" also overpromises. Research by Kevin Hall and colleagues at the US National Institutes of Health showed that weight loss slows over time as your body gets lighter and needs less energy, so that old rule predicts far more loss than really happens over months.

Fix: judge progress over four weeks, not four days, and expect your calorie target to need small adjustments as you get lighter.

6. You're moving less than before (without noticing)

When you eat less, your body quietly tries to save energy. You fidget less, take the lift instead of the stairs, and sit more. On top of that, a lighter body simply burns fewer calories doing the same things. Together, these can shrink the deficit you thought you had.

Fix: keep your daily steps up. A steady step count is one of the simplest ways to protect your deficit while you diet.

7. Poor sleep and low protein make everything harder

In a study in the Annals of Internal Medicine, people on the same diet lost 55% less fat when they slept 5.5 hours a night instead of 8.5 hours, and they felt hungrier. Short sleep makes you hungrier and makes food choices harder.

Protein helps on the other side: it keeps you fuller for longer and helps you keep your muscle while you lose fat. If most of your meals are mainly carbs, you'll probably feel hungry all day.

Fix: aim for 7 to 9 hours of sleep and include a good source of protein in every meal. Not sure how much? See our guide on how much protein you need a day.

When to talk to a doctor

If you have tracked carefully for several weeks and nothing changes, or your weight is changing quickly without a clear reason, speak to a doctor. Some medical conditions, such as thyroid problems, and some medications can affect weight and appetite, and they are worth ruling out.

The short version

• Most of the time it's hidden calories: oil, drinks, snacks and bigger portions.
• Look at weekly totals and weekly average weight, not single days.
• Expect 0.5% to 1% of your body weight a week, and adjust as you go.
• Keep your steps up, sleep well and eat protein at every meal.

The fastest way to find your leak is to track honestly for two weeks. If writing everything down sounds painful, that's exactly what we built AIMS for: you just text it what you ate, and it does the counting.