10 Reasons Your Diet Isn’t Working

Following your diet plan to the letter, but can’t lose weight? According to research by XLS Medical Group, 72% of UK adults who attempted to diet last year felt they had failed within the first month. We investigate 10 of the most common reasons diets fail – read on to find out what they are, and how to beat the stats…

1. Impatience

You lost a few pounds over the first few weeks but now you seem to have reached a plateau. Here’s the bad news: most of that weight was excess water. The good news, though? You are losing fat; it’s just a much slower process, and it’ll take a bit of time to see results.

The solution: Keep going!

2. Your body is defending its ‘happy weight’

When it comes to weight, our body doesn’t like being pushed out of its comfort zone, according to neuroscientist Sandra Aamodt, author of Why Diets Make Us Fat. Lose more than a few pounds and the defence mechanisms kick in, causing your metabolism to slow down and calorie burning to grind to a halt.

The solution: Ditch the calorie counting and let your body take the lead. Build regular exercise into your schedule, cut out processed foods and focus on eating mindfully, paying attention to the signals your brain and body are sending you.

3. Your plates are too big

You might be eating the right foods, but are you watching your portion sizes? We consume up to a third more when we use a larger plate, bowl or serving spoon.

The solution: Downsize. Or take the guesswork out of portion control with a Diet Plate and Bowl.

4. You’re underestimating your calorie intake

According to research published last year, the average Brit underestimates their calorie consumption by as much as a third. That sneaky Quality Street you were offered by your colleague this morning? The handful (or two) of salted peanuts you grabbed at the pub? The garlic bread you shared before your salad arrived? The chip (or six) you swiped from his plate? They all count, and they could be adding up much more quickly than you realise…

The solution: Track everything which passes your lips using a food tracking app like Lose It! Read the labels. And don’t forget to check nutritional information online before you eat out. 

Read our guide to eating out on a diet.

5. You’re drinking your calories

Do you only bother counting ‘solid’ calories? Then you might be shocked to learn that your daily coffee shop fix could contain more calories than your dinner. A Starbucks Grande Signature Hot Chocolate made with semi-skimmed milk contains a whopping 537 calories – that’s more than a Big Mac. Even a Skinny Latte packs a not-inconsequential 131. Partial to a sneaky Friday night treat? A large glass of wine will set you back around 200 calories, whilst a margarita will add 250 to your daily tally. Been knocking back the fruit juice instead? It’s not necessarily the virtuous choice you might imagine – a large glass could pack up to 150 calories.

The solution: Drink plenty of water, switch fruit juice for vegetable-based smoothies and dial back your wine habit. Try replacing milky and/or sugary hot drinks with ginger or peppermint tea.

6. You’re drinking diet drinks

They might be calorie-free, but research suggests that artificial sweeteners could still encourage weight gain. Scientists believe that they trigger hormonal changes which stimulate appetite and encourage the body to store fat. On average, the waist measurements of people who drink two or more diet soft drinks a day increase by five times as much as non-drinkers over time.


The solution: Not a fan of plain water? Add flavour with a fruit infuser water bottle.

7. You’re not eating enough

Believe it or not, eating too few calories could hinder fat burning. If your body thinks it is ‘starving’, it will try to cling onto fat reserves by slowing your metabolism down, making it harder to shift those stubborn pounds.

The solution: Nutritionists recommend eating at least 1,200 calories a day in order to maintain sustainable weight loss. If you’re on an intermittent fasting plan, such as the 5:2, don’t be tempted to skip ‘cheat’ days – they wake your metabolism up and give it a chance to ‘reset’.

8. You’re not eating enough fat

An essential fatty acid deficiency could not only damage your health, but encourage your body to store fat and resist weight loss in order to conserve its stores.

The solution: Include a small portion of healthy fats (e.g. nuts, seeds, avocado, olive oil, coconut oil) with every meal or snack. And yes, cheese counts. Portion size is still key, though! 

Learn which fattening foods actually help you slim down… 

9. You’re sleeping too little – or too much

Sleep for fewer than six hours a night on a regular basis and stress hormones will encourage your body to store fat, particularly around the midsection. Irritatingly, new research suggests that sleeping for more than 8 hours could also have similar effects!


The solution: Aim for 6-7 hours a night. If you have a late night or early start, a short nap can negate the impact of sleep deprivation. 

Discover how to sleep yourself slim. 

10. You have your dinner after 7pm

Want your liver to burn stored fat while you sleep? Then it needs time to process your dinner before you go to bed, say scientists.

The solution: Try to avoid eating between 7pm and 6am, or for 12 hours between dinner and breakfast.

Learn more about how your everyday habits could be stopping you losing weight. 

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