Eight foods that could ruin your diet

Nuts-A handful of nuts are a fantastic snack in between meals, but there is a fine line between satisfying your appetite and overdoing it.
Nuts have a very high fat content (around 50g of fat per 100g) but this is mainly monounsaturated fat, which is less adept at making you pile on the pounds than saturated fat and has been shown to lower cholesterol and help prevent heart disease.

However, and as with most foods high in fat, eat too many and you will find it harder to lose weight.

Try just a palm-full to keep you going. Brazil nuts, almonds, macadamias and walnuts are particularly good, while peanuts and cashews aren't so forgiving on your waistline.

And it should go without saying that anything that has been dry roasted or coated in salt is a no-no...

Orange juice- A glass of OJ or other fruit juice delivers a considerable vitamin C punch, along with other vital nutrients.

However, a medium-sized glass of orange juice can contain as much as 200 calories - which makes gulping it down along with several refills a serious dieting hazard.

If you do drink fruit juice, try and make sure it is 100% freshly squeezed as cheaper brands or those made mostly from concentrate usually contain unnaturally high levels of sugar.

Research has shown that these drinks pose a diabetes risk - so stick to water instead.

Sugar-free treats-Never has the expression 'too good to be true' been more appropriate.

Sugar-free chocolate, biscuits and other naughty snacks have to get their taste from somewhere, which usually means they are high in fat or laden with artificial sweeteners.

Research has shown that when your body detects a sweetener, it tells itself to hold on to stores of fat.

And, quite frankly, we'd rather have the natural sugar, so ignore the sugar-free options and reward yourself with a normal treat every so often - just as long as it is in moderation.

Cereal bars-Many cereal bars are packaged and marketed as if they are the answer to your hunger pangs.

However, many of them are still high in sugar and, most of all, fat and they could in fact be just as bad for you as a bar of chocolate.

Make sure you check the packaging to see if a cereal bar is all it promises to be, otherwise switch to fruit like grapes or raisins to satisfy your sweet tooth.

High-street sandwiches-Do you enjoy swimming in mayonnaise? No? Well neither does your sandwich, yet popular high-street outlets insist on drowning their produce in the stuff, which ups the calorie and fat content considerably.

Because you can never really know what goes in them, shop-bought sandwiches are littered with diet traps and can contain as much as 1,000 calories - half of your daily recommended allowance.

They can also be unnecessarily high in salt and you are much better off buying the ingredients yourself and preparing your own calorie-controlled lunchbox.

Muesli-Make no mistake - muesli is crafty. It may look like the healthiest breakfast option, packed with fruit, oats and other good stuff.

However, all that dried fruit, nuts and roasted ingredients (especially in the luxury brands) can add up to a heck of a lot of fat and as much as 500 calories a bowl.

At that rate, you might be better off with a bacon sandwich...

Even better, though, is to stick to mixing your own oats with some raisins and using skimmed milk or - best of all - eating porridge.

Avocado-While it feels wrong to say anything bad about lovely, gorgeous, tasty avocadoes, the truth is that they do contain a lot of fat, thus the nickname "butter pear".

Avocadoes are wonderfully nutritious but contain around 30g of fat - half your daily allowance.

Once again we are thankfully talking about the good kind of fat, monounsaturated, which is thought to lower cholesterol, but you should still go easy on them and choose leaner fruit and veg if your main goal is to lose weight.

Milk-Milk in coffee, milk in tea and milk on your cereal... it is easy to forget the calories you consume by stealth, and milk is one of the biggest pitfalls.

A 200ml glass of milk (not very much) contains around 100 calories, and these soon add up.

You should not shun dairy altogether; cheese, yoghurt and milk are fantastic sources of calcium which helps to keep your bones and teeth strong.

However, try to monitor your intake and make sure you include the calories and fat in milk in your daily food diary.

Avoid whole fat milk - semi-skimmed is fine but, and we promise it is not that bad, skimmed should be your number one choice.