Why Am I Not Losing Weight? 10 Honest Reasons

If you’re asking “why am I not losing weight?” despite trying hard, you’re not alone. A weight loss plateau is frustrating, but there’s almost always an explanation. Here are the 10 reasons we see most often, and a simple plan to get things moving again.

Why am I not losing weight? 10 common reasons

Before you change anything, it helps to know that a slow week is normal. Fat loss is rarely a straight line. Look through these reasons honestly and you’ll usually find one or two that apply to you.

1. You’re eating more than you think

This is the most common reason by far. Cooking oil, sauces, snacks while making dinner and “just a bite” of the kids’ food are easy to forget. Most people underestimate their intake without realising. It’s not dishonesty, it’s just hard to judge portions by eye.

2. The weekends undo the week

Five careful weekdays followed by a big Friday night, a brunch and a Sunday roast can cancel out the deficit you built. Your body runs on a weekly total, not a Monday-to-Friday one.

3. Liquid calories

Alcohol, large milky coffees, smoothies, juices and fizzy drinks add a lot of calories without filling you up. They are often missing from food diaries completely.

4. Water retention is hiding fat loss

A salty meal, a hard workout, a high-carb day, poor sleep or the menstrual cycle can all make you hold extra water for a few days. The scale can stay flat or even rise while you’re still losing fat underneath.

5. You’re moving less without noticing

When you diet, you can unconsciously move less: fewer steps, more sitting, less fidgeting. This everyday movement (sometimes called NEAT) can make a big difference to how much you burn. Tracking how many steps a day you take is a simple way to keep it up.

6. You’re building muscle

If you’ve recently started strength training, you might be gaining some muscle while losing fat. The scale moves slowly, but your clothes fit better and your measurements drop. This is a good problem to have.

7. Poor sleep and high stress

Short sleep and constant stress tend to increase hunger and cravings and make it harder to stay consistent. They also make you more likely to skip training and move less.

8. Not enough protein

Low protein diets leave you hungrier and make it harder to hold on to muscle. Building each meal around a decent portion of protein makes a deficit much easier to stick to.

9. You’re weighing at the wrong times

Weighing after a meal, at different times of day, or comparing one day to the next gives you misleading numbers. Daily weight naturally jumps around. Only trends over weeks tell you much.

10. A medical cause or medication

Some medical conditions, such as an underactive thyroid, and some medications can affect weight and appetite. If you’ve been genuinely consistent for a long time with no change, it’s worth speaking to your GP.

What to do about a weight loss plateau

Instead of cutting calories drastically or giving up, follow these steps:

1. Track everything honestly for two weeks. Weekdays and weekends, drinks included, using an app or a written diary.
2. Weigh yourself three to seven times a week, first thing in the morning after the toilet, and work out your weekly average.
3. Measure your waist once a week at the same point, usually level with your belly button.
4. Check your daily steps and bring them up if they’ve dropped.
5. Only then adjust. If the weekly average and waist haven’t moved for two to three weeks, reduce intake by around 100-200 calories a day or add more movement.

Our calorie deficit UK guide explains how to set your target and adjust it properly.

Look beyond the scale

Other signs of progress matter too: clothes fitting more loosely, more energy, better sleep and lifting heavier weights in the gym. If these are improving, you’re usually on the right track even when the scale is being stubborn.

The scale only measures total weight. It can’t tell fat from muscle or water. That’s why we use waist measurements, progress photos and InBody body composition scans with our clients. An InBody scan in London shows your fat mass and muscle mass separately, so you can see whether you’re losing fat even when the scale is slow.

What not to do

• Don’t slash calories to very low levels. We never suggest going below around 1,200 a day without medical supervision.
• Don’t add hours of extra cardio out of frustration.
• Don’t judge your progress on a single weigh-in.
• Don’t turn to pills or extreme fasting.
• Don’t change five things at once. Adjust one thing, then give it two weeks so you know what worked.

See your GP if you’ve been consistent for several months without any change, if you’re gaining weight without explanation, or if you have symptoms such as constant tiredness, feeling cold, changes to your periods, or you’ve started a new medication. A GP can check for medical causes.

Getting help to break the plateau

Sometimes you just need someone else to look at the numbers. Our weight loss coaching includes a food plan, weekly check-ins and regular InBody scans, so a plateau gets spotted and fixed within days rather than months. See how our weight loss personal training in Archway works.

Want this coached 1-to-1? Stuck for weeks? We’ll find out why and fix it with you. Book a free consultation at our Archway studio.

Frequently asked questions

Why am I not losing weight in a calorie deficit?

Most often your intake is higher than you think, especially at weekends or through drinks, or water retention is masking fat loss. Track honestly for two weeks and compare weekly averages before changing anything.

How long does a weight loss plateau last?

A short stall of one or two weeks is often water retention and passes on its own. If your weekly average and waist haven’t changed for two to three weeks, it’s time to adjust your food or activity.

Can building muscle stop you losing weight?

It can slow the change on the scale, especially for beginners, even while you’re losing fat. Waist measurements or an InBody scan show what’s really happening.

When should I see a GP about not losing weight?

If you’ve been consistent for months with no change, are gaining weight without explanation, have symptoms such as constant tiredness, or have started new medication, speak to your GP.

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