Why Can’t I Lose Weight? Common Mistakes and How to Fix Them
You’re eating well. You’re moving more. You’ve even sworn off biscuits (well, mostly). So why won’t the scales budge? Why can’t I lose weight?
It’s one of the most frustrating parts of trying to lose weight. You feel like you’re doing everything right, yet nothing seems to be happening. The good news? This is incredibly common, and there are usually clear reasons behind it. Even better, most of these reasons are fixable.
In this guide, I’ll break down the 9 most common reasons why weight loss stalls, the mistakes that might be holding you back, and practical steps to get back on track. No fad diets, no miracle cures—just honest, actionable advice to help you move forward.
1. You Might Be Eating More Than You Think
This is one of the most common reasons weight loss stalls. Many of us underestimate how much we’re eating, and it’s not always obvious why. So when you think, why can’t I lose weight? This might be your answer.
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? Just two to three tablespoons.
Sound smaller than what you usually serve yourself? You’re not alone.
What You Can Do
Focus on Small Changes: The NHS recommends aiming to lose 0.5 to 1kg per week. Small, consistent changes are more sustainable than drastic cuts.
Track Your Food: Write down everything you eat for a week, including snacks and drinks. You don’t have to do this forever, but even a short period of tracking can reveal where extra calories are sneaking in.
Measure Portions: Use kitchen scales or measuring cups to get a better sense of portion sizes.
2. You’re Not Moving as Much as You Think
Exercise is fantastic for your health, but it’s easy to overestimate how many calories you’re burning. For example, a 30-minute walk might burn around 150 calories, but a large latte and muffin can easily add up to 600 calories.
What You Can Do
Think Beyond the Gym: Take the stairs, park further away, or do more housework. These small choices add up over time.
Increase Activity Levels: The NHS recommends at least 150 minutes of moderate activity per week. If weight loss has stalled, the Mayo Clinic suggests increasing this to 300 minutes.
Add Strength Training: Building muscle helps your body burn more calories at rest.
3. You’ve Hit a Weight Loss Plateau
A plateau isn’t a sign that something is wrong—it’s a sign that your body has adapted. When you first cut calories, you often lose weight quickly, partly due to water weight. But as you lose weight, your metabolism adjusts. A lighter body needs fewer calories to function, so the same plan that worked at the start may no longer create a calorie deficit. Could this be your answer to why can’t I lose weight, when you did before?
What You Can Do
Mix Up Your Workouts: Try new activities or increase the intensity of your current routine. For ideas, check out this guide to overcoming a weight loss plateau with exercise.
Reassess Your Habits: Are you still sticking to your plan as closely as you were at the start? Small slips can add up.
Adjust Your Calorie Intake: As your weight changes, your calorie needs change too.
4. Your Diet Doesn’t Suit Your Lifestyle
The best diet is the one you can stick to. If your plan doesn’t fit your lifestyle, it’s unlikely to work long-term. For example:
- If you love big, filling meals, a plan built around small portions might leave you feeling deprived.
- If you eat out regularly, a diet with no flexibility for restaurants will quickly become frustrating.
What You Can Do
Focus on Sustainability: A plan that feels manageable is far more likely to lead to long-term success.
Choose a Plan That Fits: Be honest about your lifestyle and preferences. This quiz can help you find a diet that suits you.
5. You’re Skipping Meals
Skipping meals might seem like a logical way to cut calories, but it often backfires. Going too long without food can lead to intense hunger later, making overeating more likely.
What You Can Do
Plan Ahead: Keep healthy snacks on hand to avoid reaching for quick, high-calorie options when hunger strikes.
Eat Regularly: A steady supply of balanced meals and snacks helps manage hunger and keeps your energy levels stable.
6. You’re Drinking Your Calories
Drinks can quietly add up to a significant number of calories. Fruit juice, smoothies, fizzy drinks, alcohol, and fancy coffee drinks are common culprits. Could this be your answer to why can’t I lose weight?
What You Can Do
Limit Juice and Smoothies: The British Heart Foundation recommends limiting these to 150ml per day.
Swap Sugary Drinks: Opt for water, herbal tea, or lower-calorie alternatives.
For tips on swapping alcoholic drinks and other beverages, this post has some useful ideas.
7. You’re Ignoring Emotional or Boredom Eating
Many of us eat for reasons other than hunger—stress, boredom, sadness, or even habit. If this sounds familiar, no diet will be fully effective until these patterns are addressed.
What You Can Do
Pause and Reflect: Ask yourself, “Am I actually hungry, or am I eating out of habit or emotion?”
Find Non-Food Comforts: Exercise, hobbies, or even a relaxing bath can provide comfort without the calorie cost.
Read More: This article on boredom eating vs hunger is a great place to start.
8. Your Goals Are Too Big
Big goals can be motivating, but they can also feel overwhelming. If your target feels far away, it’s easy to lose steam.
What You Can Do
Set Smaller Goals: Break your larger goal into smaller, achievable milestones. Celebrate each win, no matter how small.
9. You’re Going It Alone
Support makes a huge difference. Whether it’s a friend, family member, or community group, having someone to share your journey with can keep you motivated. Could this be your answer to why can’t I lose weight?
What You Can Do
Find Accountability: Join an online community, a local group, or even just check in with a friend regularly.
Use Free Resources: The NHS 12-week weight loss plan offers structured guidance and support.
Frequently Asked Questions
Why can’t I lose 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 be maintained than rapid weight 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.
Why can’t I lose weight? Could it be a medical condition?
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.
Why can’t I lose weight? 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 key is to keep going, keep tweaking, and not let a rough patch derail your progress. Remember, everyone will have times when they ask themselves, why can’t I lose weight? Just keep going!
Remember, small changes add up over time. Celebrate every win, no matter how small, and focus on building habits that support your long-term health.
If you found this guide helpful, let me know in the comments—or share your own tips for overcoming weight loss struggles. Let’s keep moving forward together!
