Foods to avoid (at all costs!) on a diet

Thought you were being healthy with that cereal bar snack? Think again. We reveal the sneaky foods that are secretly ruining your diet

Foods to avoid on a diet

Are you wondering why you can't lose weight despite going on a strict diet? Or maybe you've just started to put on weight even though you always choose the healthy option?

It might come as a surprise that sometimes the healthy option is not always the best option for weight loss. And there are some foods to avoid for weight loss that usually you'd consider to be 'healthy'.

We've rounded up some of your favourite foods that could be really jeopardising your efforts to lose weight, alongside the most common diet spoilers and the best alternatives.

Shop-bought sandwiches

When it's lunchtime and you're stuck for what to eat it's so easy to just grab a sarnie, and there are so many tempting varieties. But did you know that some shop-bought sandwiches contain as many as 900 calories? A hefty amount when you consider that a small takeaway burger is around 500 calories!

What to eat instead If you make your own sandwiches then you can ensure you use your favourite low-fat spread, a low-fat filling and stuff it with salad, which will fill you up and lower the calories. But if you're tired of sandwiches or you don't like the way they go soggy in your lunchbox then try using pitta bread instead, which doesn't tend to go as soggy and is lower in calories.

Cinema popcorn

We all like to have a snack at the cinema, but before you part with your cash be careful of what you're buying. The obvious unhealthy things to avoid are sweets, cheese-covered nachos and maybe a hotdog but did you know that popcorn is actually the worst of the bunch? A large sweet-flavoured popcorn holds a whopping 1,800 calories and even a bag of salty isn't much better at around 1,779 calories. Popcorn is often thought of as a healthy snack so the fact one bag can hold your entire daily calorie allowance (or the equivalent to a large curry, sides and two beers) is shocking!

What to eat instead Making popcorn yourself at home makes it a lot healthier. Buy a bag of un-popped maize kernels from the supermarket and pop them yourself before you go out. That way, you know exactly how much butter, salt or sugar you're adding - saving you calories and cash! Try sprinkling some spices over it as an alternative, healthier option to sweet or salty.

Shop and restaurant salads

You think you're being good by ordering the healthy option on the menu but restaurant and shop-bought salads often contain high amounts of fat because of the sauces and accompaniments, such as egg mayonnaise and Caeser dressing. A recent survey found one of the salads at a large chain of pizza restaurants contained nearly 1000 calories!

What to eat instead You can still tuck in to a salad, just ask for dressing on the side and stay away from the cheese and croutons. Or ask for balsamic vinegar or olive oil, which is a good fat and great for your skin and heart. After a bit of recipe inspiration? Try one of our healthy salad recipes!

Nuts and dried fruit

We're always told to snack on nuts and dried fruit when we're watching our weight but it's easy to overdo it. Although nuts and dried are fruit are better snacks than crisps or chocolate, nuts are packed with calories, around 500 calories and 50g of fat per 100g. And dried fruit has loads of sugar, around 64g of sugar and 240 calories per 100g, because even though it's fruit sugar it still turns to fat if you don't burn it off.

What to eat instead There's no doubt that nuts are a great source of protein and they also contain good fats so just stick to one small handful, and for the record a handful is the size of your flat palm. Generally speaking, this is around 10-12 almonds, Brazil nuts, walnuts or macadamia nuts. Likewise, the right portion of dried fruit is the same, but to keep the calories low, choose between one portion of nuts or dried fruit per day.

Sugar-free sweets and chocolate

It's a chocoholic's dream, sugar-free chocolate! But chocolate and sweets that are sugar-free or low in sugar are usually full of artificial sweeteners and new research suggests that when your body has these sweeteners it sends a message to your digestive system to hold on to any fat. So even though you are going light on the sugar, your body is being super-efficient at grabbing and storing fat.

What to eat instead If you can stop at just one small piece of chocolate or one or two sweets then go for the the regular, full-fat, full-sugar varieties. But if you know that one usually leads to a whole packet then don't go near them. Try to work out if you are really hungry - do you really need that chocolate? What's your craving about? Are you just bored or feeling down? If you can't resist your craving, have a low-calorie hot chocolate, a few squares of dark chocolate, or check just how bad your favourite chocolate bar is - so you can make an informed decision when it comes to a treat!

Healthy cereal bars

They're convenient, tasty and full of goodness. Or are they? Most cereal bars contain oats, which are good carbohydrates, i.e. they release sugar slowly into your body so you don't get that energy slump halfway through the day. But they often also contain lots of refined sugar and fat to bind them together. In fact you'd be surprised which cereal bars are the best and worst for your diet!

What to eat instead Fruit: Small, portable, low-fat and full of vitamins and minerals, it's a great way to start the day. But if you really want that sweet, slightly stodgy feeling that cereal bars can give you why not try making healthy flapjacks. Swap the butter for low-fat margarine, and using half oats half high-fibre breakfast cereal or Muesli.

Takeaway coffee

What did we do before meeting up for full-fat triple mocha frappacinos? Our love of takeaway coffee has helped to add inches to our waistlines with the average sized latte weighing in at around 220 calories and 11g of fat.

What to eat instead Losing the latte pounds is easy, just swap your usual order for skimmed or semi-skimmed milk, or soya if you prefer. And don't forget to skip the whipped cream, syrups and chocolate flakes.

If you fancy a change from coffee try making a juice at home, but beware of the ready-made shop-bought varieties. You might think that swapping your coffee for a shop-bought smoothie is a better option, but think again! Although they can up your five-a-day quota they can still be high in fat and very high in sugar. Yes, it's fruit-sugar but if you don't burn off the sugar it turns to fat.

Diet drinks

There are some nutritionists who believe that diet drinks are just as bad as regular drinks. Diet drinks have less sugar, which is better for your waistline and your teeth but there's some research that suggests that sweeteners in the drinks increase your appetite and create cravings, so even though you might be drinking a diet cola, you'll soon want a packet of peanuts or a bar of chocolate!

What to eat instead It's boring and you've heard it before but water is the best option. It's great for your skin, it fills you up and helps your body to burn fat. If you can't stand the taste of water add some fresh fruit juice instead.


Just one glass of wine can't hurt the diet, surely? Well, just one glass of wine contains around 80 calories. But how many of us can really stick to just one glass? And even if you can you will be more inclined to say, 'sod the diet!' and tuck into the sort of high-fat, high calorie food that you're trying to avoid.

What to have instead Try a low-calorie wine or beer or mix your drink with sparkling water, or think of the 'empty' calories in alcohol and go for a fruit juice instead.


Who'd have thought that a pot of organic yogurt with fruit and nuts is full of fat and sugar? Some of those tempting yogurts can have as much as 240 calories! And even the low-fat variety can be just as bad. Even though they have less fat they can have double the sugar.

What to eat instead Yogurt is good for you, it has loads of calcium and it's soothing for your digestion, especially if you go for bio-yogurt. Don't be swayed by the labels, just go for a low or lower-fat plain variety and add your own fruit and nuts - then you can control exactly how many calories you have.

Breakfast cereal

There's no doubt that breakfast is the most important meal of the day, it kick-starts your metabolism and fills you up until lunch but choosing the right breakfast cereal is crucial if you want to lose weight. Some cereals, although they look healthy because they have dried fruit or wheat in them they still contain as much as sugar as a chocolate bar or as much fat as a slice of cake!

What to eat instead If you love your cereal then choose a high-fibre variety and one that is fairly plain, i.e. not sugar-coated, containing chocolate, nuts or toffee pieces. Alternatively, take a break from cereal and try wholegrain toast, low-fat plain yogurt with honey or chopped fruit.

Jessica Dady
Food Editor

Jessica Dady is Food Editor at and has over 10 years of experience as a digital editor, specialising in all things food, recipes, and SEO. From the best food hampers to cookbooks, from the best cake stands to kitchen appliances, Jessica has a wealth of knowledge when it comes to must-have food products. A passionate baker, she spends some of her time creating celebration cakes for friends and family including her two lucky children.