It's diet time

Are your jeans a little tighter after the Christmas indulgence? Some people will turn to diet books to find some weight loss advice. There is a dizzying array of literature about losing weight but is any of it actually based on good science? Leila Sattary investigates fad diets and health foods

In 2011, we live with a more obese population than ever before and yet we know more about food and nutrition. The importance of healthy eating is right up in our consumer faces. No added sugar, with vitamins and minerals, high fibre, low fat. With all these healthy foods to choose from, why are we still getting fatter?

The general population knows more about cholesterol and heart disease than ever before and many of us have seen its direct impact on friends and family. We have the knowledge but we are not taking action. Part of the problem is bad science and bad advertising. The companies who are pushing health foods still want us to consume as much of them as possible. Consumerism and cutting back do not go well together.

Healthy yoghurts branded as low fat are usually high in sugar, and vice-versa. Kids’ breakfast cereals that claim to be high in fibre are usually still loaded with sugar. Consumers need to check the labels, and I mean the actual nutrition information on the back of packs.

Probiotic yoghurts are a personal bugbear of mine. The ads get some of the basics right – probiotics are ‘good’ bacteria that live in our intestines. What they do not tell you is that healthy guts are already loaded with probiotics and drinking one of their yoghurts a day is the analogy of adding a bucket of water to an already full swimming pool – it’s not going to make a significant difference. Developing foods with prebiotics, which encourage the growth of probiotics in our bodies, seems like a good idea to me. However, the only food I’ve seen advertised with a prebiotic focus is my cat’s food.

When it comes to losing weight it is really quite simple. You need to burn more calories than you eat to drop the pounds. Of course, the types of foods those calories consist of will impact on your health – many diets confuse being slim with being healthy. If you go back to basics, losing weight is a simple application of the first law of thermodynamics.

Fad diets promise a thinner and more attractive you by following a strict set of rules that govern the types of food you eat. Probably the most famous diet of all time was the Atkins diet. Robert Atkins was an overweight cardiologist that came up with a set of diet rules which, if followed strictly, helped people lose weight easily. The rules are simple – eat protein and fat and the occasional fruit and veg but have next to no carbohydrates or sugar. What set the Atkins diet apart from other diets was that there was no control on the calorie intake – you can eat as much as you like as long as it is protein or fat. Scientists were up in arms against the diet, firstly because promoting people to eat lots of fat seemed like a very bad idea, and that there was no evidence or scientific understanding of why the diet worked.

Atkins’ theory was that burning fats takes more energy than burning carbohydrates, so if more of your diet was made up for fat then you use more energy to process it. A number of scientific studies followed which showed that there was no significant difference in the amount of energy used to burn fats verses carbohydrates. However, studies continued to show that people lost more weight on the Atkins diet than on a standard low fat, low calorie diet.

It took a number of years until the mystery of the Atkins diet came to conclusion. When Atkins dieters keep a strict diary of what they eat it showed that they actually eat fewer calories despite being allowed to eat as much as they like of particular foods. It was the high protein in the Atkins diet that kept appetites at bay. Cutting out carbohydrates had little to do with the weight loss of the dieters. They simply did not get very hungry and so consumed less.

The Atkins diet is a classic example of something that encouraged millions across the world to eat the wrong foods for the wrong reasons.

Everyone is looking for that magic pill that makes you lose weight but I am fairly sure it does not yet exist, despite various adverts to the contrary. Meanwhile, it seems simple to me – we need to eat less in general, with lower proportion of fat and perhaps even do a bit of exercise from time to time. I look forward to a day when a proper book on nutrition is published to start educating people about food. When we are bombarded by lies and fabrication about the science of food it is no wonder we are still making the wrong decisions about our diets.