Why Can’t I Lose Weight? Common Mistakes and How to Fix Them
You’re eating well. You’re moving more. You’ve sworn off biscuits (mostly). So why won’t the scales budge?
It’s one of the most frustrating things about trying to lose weight. You feel like you’re doing everything right, yet nothing seems to be happening. The good news is that this is incredibly common, and there are usually clear reasons behind it. Better still, most of them are fixable.
This post breaks down the most common reasons why weight loss stalls, what mistakes might be getting in the way, and what you can actually do to start seeing results again. No fad diets, no miracle cures. Just honest, practical advice. If you are wondering, why can’t I lose weight, then maybe this post is for you?
Why Can’t I Lose Weight – You Might Be Eating More Than You Think
This is the big one. Most people underestimate how much they eat, and it’s not always obvious why.
Portion sizes have crept up over the years. What looks like a “normal” bowl of pasta might actually be two or three portions. According to the British Dietetic Association (BDA), a single cooked portion of pasta is around 150g. A portion of cooked meat is roughly the size of a deck of cards. A portion of rice is just two to three tablespoons.
Sound smaller than what you serve yourself? You’re not alone.
A simple way to get a better idea of what you’re eating is to track your food for a week, honestly and accurately. You don’t have to do it forever. Even a short period of tracking can open your eyes to where extra calories are sneaking in. That handful of nuts, the splash of oil in the pan, the bite of your child’s dinner — it all adds up.
The NHS recommends aiming to lose 0.5 to 1kg per week, which means you need a modest calorie deficit each day. You don’t need to slash your intake dramatically. Small, consistent changes tend to work far better than dramatic ones.
Why Can’t I Lose Weight – You’re Not Moving as Much as You Think Either
Exercise is brilliant for your health, but many people overestimate how many calories they burn during a workout and then reward themselves with food that more than cancels it out.
That 30-minute walk might burn around 150 calories. A large latte with a muffin can be close to 600. The maths doesn’t always work in our favour.
The NHS guidelines suggest getting at least 150 minutes of moderate activity each week, broken down into shorter sessions if needed. The Mayo Clinic notes that if weight loss has stalled, bumping activity up to 300 minutes per week can help break through a plateau. Adding some strength or resistance training on top of cardio is also worth doing, as building muscle helps your body burn more calories at rest.
Think beyond the gym, too. Taking the stairs, parking further away, doing more around the house — these small choices add up over time.
Why Can’t I Lose Weight – You’ve Hit a Weight Loss Plateau
Here’s something that surprises a lot of people. A plateau is not a sign that something is wrong. It’s actually a sign that your body has adapted to what you’ve been doing.
When you first cut calories, you often lose weight fairly quickly. Some of that early loss is water weight, released as your body burns through glycogen stores. But as you lose weight, your metabolism adjusts. A lighter body simply needs fewer calories to function. So the same plan that worked brilliantly at the start may no longer create a big enough calorie deficit to keep weight coming off.
As the Mayo Clinic explains, when the calories you burn equal the calories you eat, weight loss stops. This is not failure. It just means it’s time to make some adjustments.
Take a look at this guide to overcoming a weight loss plateau with exercise for some practical ideas on what to try next.
Why Can’t I Lose Weight – Your Diet Doesn’t Suit Your Lifestyle
There are hundreds of diets out there, and most of them will work to some degree — but only if you can actually stick to them. A plan that doesn’t fit the way you live is almost certain to fail, no matter how effective it looks on paper.
If you love big, filling meals but you’re following a plan built around small portions and light eating, you’re going to struggle. If you eat out regularly, a diet that gives you no flexibility for restaurants will quickly become unsustainable.
Choosing the right diet for your lifestyle really does make a difference to your long-term success. Have a read through some of the options available and be honest with yourself about what fits your daily routine. If you have no idea which to try, then check out my quiz to find the diet for you!
Why Can’t I Lose Weight – You’re Skipping Meals
Skipping meals sounds like a logical way to cut calories. In practice, it often backfires. The NHS advises against skipping meals because it can lead to increased hunger later in the day, which makes overeating much more likely.
Going too long without food can also make you reach for quick, high-calorie options when hunger finally takes over. A steady supply of balanced meals and healthy snacks throughout the day is usually far more effective at managing hunger and keeping overall intake in check.
Why Can’t I Lose Weight – You’re Drinking Your Calories Without Realising It
Food gets all the attention when it comes to weight loss, but drinks can quietly pile on the calories too.
Fruit juice, smoothies, fizzy drinks, alcohol, fancy coffee drinks — these can all be surprisingly calorie-dense. The British Heart Foundation recommends limiting fruit juice and smoothies to 150ml per day. On average, most women need around 2,000 calories a day and men around 2,500. A large glass of orange juice alone can account for nearly 10% of that without making you feel full at all.
Swapping sugary drinks for water, herbal tea, or lower-calorie alternatives is one of the easiest wins when it comes to reducing overall calorie intake. For tips on swapping alcoholic drinks and other beverages, this post has some useful ideas.
Why Can’t I Lose Weight – You’re Ignoring Emotional or Boredom Eating
Weight loss is not just about food and exercise. It’s also about understanding why you eat.
Many people eat when they are bored, stressed, sad, or anxious — not because they are hungry. If this sounds familiar, no diet in the world will be fully effective until those patterns are addressed.
Ask yourself: am I actually hungry, or am I eating out of habit, comfort, or boredom? Even becoming aware of the difference can be a powerful first step. This article on boredom eating versus hunger is worth a read if you think this might be playing a role for you.
Finding non-food ways to reward yourself or manage difficult emotions can also help. Things like exercise, a new hobby, a relaxing bath, or a good box set give your brain the same kind of comfort without the calorie cost.
Why Can’t I Lose Weight – You’re Setting Goals That Are Too Big
Big goals are motivating right up until they start to feel impossible. Then they become demoralising.
If your target feels far away, it is easy to lose steam and give up before you’ve had a chance to see real progress. Breaking a larger goal into smaller, achievable milestones makes the whole process feel much more manageable.
Instead of focusing on a large total amount of weight to lose, try focusing on losing a few pounds at a time. Celebrate each small win. Every 5 pounds down is progress worth acknowledging.
Why Can’t I Lose Weight – You’re Going It Alone
Having support makes a real difference. People who share their goals with a friend, family member, or community group tend to do better than those who try to manage everything on their own.
Whether it’s a weekly weigh-in with a friend, an online community, or a more structured group programme, accountability helps. On days when motivation dips, knowing someone else is cheering you on (or checking in on your progress) can be just enough to keep you going.
There are free NHS resources available too, including the NHS 12-week weight loss plan, which offers structured guidance and support.
What You Should Do Next
If you’ve been struggling to lose weight and can’t work out why, start here:
- Be honest about portions. Track your food for a week to get a realistic picture of what you’re eating.
- Move more in small ways. You don’t have to overhaul your entire routine overnight.
- Find a plan that actually suits you. Not one that worked for someone else, but one that fits your life.
- Don’t skip meals. Regular eating keeps hunger in check and helps avoid overeating later.
- Look at your drinks. Calorie-heavy drinks are easy to overlook and easy to change.
- Address the emotional side. If you eat in response to stress or boredom, that’s worth working on.
- Break your goal into smaller steps. Small wins build momentum.
- Get support. You don’t have to do this alone.
If you’ve been following a healthy plan for a while and progress has simply stalled, the Mayo Clinic recommends reassessing your habits, adjusting your calorie intake slightly, and increasing your activity levels. Speak to your GP or a registered dietitian if you’re genuinely stuck. Sometimes a professional perspective makes all the difference.
Frequently Asked Questions For Why Can’t I Lose Weight
Why am I not losing weight even though I’m eating less and exercising?
It’s likely down to one of a few things: your body has adapted and your metabolism has slowed, you may be eating slightly more than you realise, or your calorie deficit isn’t quite big enough. A plateau is normal and doesn’t mean your approach isn’t working. Small adjustments to food intake or activity levels usually help.
How much weight should I aim to lose each week?
The NHS recommends aiming for 0.5 to 1kg (roughly 1 to 2 pounds) per week. Losing weight gradually is more sustainable and more likely to stay off than rapid loss.
Is it normal to stop losing weight after a while?
Absolutely. Almost everyone hits a plateau at some point. As you lose weight, your body needs fewer calories, so the same habits that led to weight loss early on may eventually maintain your weight rather than reduce it further. Adjusting your plan slightly will help you move past it.
Could a medical condition be stopping me from losing weight?
Yes, in some cases. Conditions like hypothyroidism (an underactive thyroid) and polycystic ovary syndrome (PCOS) can make weight loss harder. If you suspect a medical reason, speak to your GP.
Do I need to exercise to lose weight?
Not necessarily, but it helps enormously. Exercise supports weight loss, improves mood, increases metabolism, and has a huge range of health benefits beyond the number on the scales. Even light activity like walking counts.
What should I do if nothing seems to be working?
Speak to your GP or ask for a referral to a dietitian or weight management service. There is professional support available on the NHS, and you don’t have to figure this out entirely on your own.
Keep Going — Progress Takes Time
Weight loss is rarely a straight line. There will be weeks where nothing moves and weeks where it suddenly does. The most important thing is to keep going, keep tweaking, and not let a rough patch send you back to square one.
As the Mayo Clinic puts it, whatever you do, don’t give up and go back to your old habits. Celebrate the progress you’ve already made and keep building on it.
