10 diet mistakes and how to beat them

You underestimate what you're eating

Studies confirm that overweight women underestimate their calorie intake by 20 per cent. It's occasional mouthfuls that are easiest to forget about - chips from your child's plate, a biscuit in the office - together with underestimating portions and forgetting the calories in drinks. It only takes 100 extra calories a day to stop you losing 10lb a year, so keep a food diary and write down every morsel that passes your lips.

You starve yourself

Many women believe they need to consume fewer than 1,000 calories a day to lose weight. Experts disagree, saying an extremely low calorie intake means your body burns muscle for fuel - and less muscle means a slower metabolism and lower calorie needs. Don't eat fewer than 1200 calories a day and do regular resistance exercise to boost muscle.

You eat with your eyes

You order a dessert when you're full, have seconds at a buffet, and buy a doughnut when you pass the bakery... Many of us find it impossible to resist delicious-looking food, regardless of whether we're hungry. That food might look good, but do you? Scrutinise yourself naked in the mirror. If you don't like what you see, store that image, then conjure it up when you're tempted to eat something just because it looks tasty.

You always use a trolley in the supermarket

The larger the trolley, the more food you'll stuff in that you don't want, and the longer you'll stay in the store. Supermarkets are designed to encourage you to buy - for example, by displaying chocolate in a prominent place or filling the store with the aroma of baking bread. If you only need a few things, use a basket so there's less room for stuff you don't need - and once it gets heavy, you won't want to cruise the aisles.

You're too hard on yourself

Banning your favourite foods means you'll feel deprived, binge on them and give up dieting altogether. Include small portions of your favourite treats and accept that lapses are a normal part of life - just get back on track tomorrow.

You blame your metabolism

A slow metabolism is rare and not usually the cause of being overweight. In fact, overweight people usually have a faster metabolism than slimmer people because their bodies burn more calories to move the extra weight! Accept that you're overweight because you eat too much food and exercise too little.

You skip breakfast

Around one in five Brits go without a morning meal - bad news because numerous studies show breakfast skippers are fatter than breakfast eaters. The reason: low blood-sugar levels, lack of energy and hunger lead skippers to calorie-packed fixes such as doughnuts, muffins and chocolate later in the day. Eat a high-fibre breakfast such as wholegrain cereal with fruit and low-fat milk or wholemeal toast with peanut butter.

You eat too quickly

It takes about 20 minutes for the brain to receive the signal that your tummy is full. No matter how much or little you eat in that time, those satiety signals won't kick in. So if you eat quickly, by the time they do you're already stuffed. Chew every mouthful 20 times, go for foods that need more chewing, use chopsticks to slow you down, and have a low-fat starter before your main.

You undo all your good work at the weekend

Studies show that while many of us eat healthily during the week, we overindulge sufficiently at weekends to stop us losing weight. Takeaways, fry-ups, pub lunches, eating out and lots of booze mean we take in more calories over two days than we've saved during the working week. Stick to healthy eating at the weekend and limit treats. Be more active with the family at weekends, too - the calories you burn will help compensate for the extra ones you take in.

You ditch dairy

Giving up milk, cheese and yoghurt seems a quick fix for saving calories, but research shows reduced-fat dairy products help our bodies burn fat, especially from our waistline. It's thought the unique combo of nutrients - and especially the calcium they contain - work their slimming magic. Choose skimmed or one per cent milk, fat-free yoghurts and reduced fat cheese. They're lower in calories but contain most of the other nutrients.