What Teen Girls Need To Know About Dieting


Dieting Wisdom For Teen Girls


I hate this time of year. The start of formal season, where high school students start to plan what they’ll wear and who they’ll take to their end of year formal.

Diets start as fads and turn into eating disorders

Diets start as fads and turn into eating disorders

Why am I such a formal scrooge? Because every year formal season reminds me that the large majority of teenage girls are desperately unhappy with their body shape and weight, so much so that they go to extreme lengths to lose weight in the months leading up to their formal. Every year I’m alarmed by the growing number of girls who, at a healthy weight, use dieting apps to restrict their calorie intake to half (or even less than half) of their recommended dietary intake.

Extreme dieting is dangerous. It’s how eating disorders start. If you have a teenage daughter, please pass on this dieting wisdom.

Carbohydrates Are Not The Enemy

Thanks to low-carb diets, a lot of people think they need to restrict their carbohydrate intake to lose weight. Not true. There are two types of carbohydrates, simple carbohydrates and complex carbohydrates. Simple carbohydrates – think chocolate, lollies, soft drink – are simple sugars that provide the body with a short, quick burst of energy. Complex carbohydrates on the other hand, found in vegetables, whole grain cereals, pasta, multigrain bread, and rice, are a longer lasting fuel.

Just like there are good fats and not so good fats, there’s good carbs and sometimes carbs. Complex carbohydrates are good carbs. Your body needs them to run properly. They won’t make you fat.

‘Energy Out’ Doesn’t Just Mean Exercise

Exercise isn’t the only way your body burns energy. Your organs – your heart, lungs, brain, and stomach – all need energy to function as well. In fact, only 20-30% of our daily calorie intake is used for physical exercise (including both planned exercise and incidental exercise like walking between classes at school), while 70% of the energy you get from food is used to keep all the systems in your body working properly.

What does this mean? You don’t need to burn off every calorie you eat. Your body will burn through most of the energy you take in just by carrying out bodily functions like breathing.

Not Eating Won’t Help You Lose Weight

Everyone has a ‘set-point’ or a healthy weight range that’s genetically determined. When you eat more or less than what your body needs it pulls out all sorts of tricks to keep you within that healthy weight range. For example, if you eat more than what you usually would in a day, your metabolism speeds up (your “energy out” increases without you having to do anything) to burn off the extra calories. It’s why you don’t suddenly put on weight after eating more than you usually would on your birthday. It’s only when you eat significantly more than what your body needs over a longer period of time (weeks and months not days) that your body struggles to compensate and you start to gain weight.

When you use extreme dieting strategies to lose weight, your body goes into fuel saving mode. It slows down your metabolism and makes your muscles work more efficiently to make the fuel it does have last longer. When you step on the scales it might look like you’re losing weight, but this is due to changes in water weight, not fat loss – you’re not actually changing your body weight.

The take home message? The more radical you are in your attempts to lose weight, the more your body will fight to keep you at your “set-point”. Eating far less than what your body needs won’t help you to lose weight.

Dr. Sarah Hughes is a clinical psychologist and the founder of Think Clinical Psychologists. She enjoys working with children, adolescents, and adults, and specialises in anxiety, depression, postnatal depression, eating disorders, self-harm, and challenging behaviour.