We think we know what to eat: less red meat and more fiber, less saturated fat and more fruit and veg, right? Wrong, according to a controversial new book by obesity researcher and nutritionist Zoe Harcombe.
In The Obesity Epidemic: What Caused It? How Can We Stop It? Harcombe charts her meticulous journey of research into studies that underpin dietary advice – and her myth-busting conclusions are startling.
Myth: The rapid rise in obesity is due to modern lifestyles
According to Zoe Harcombe, the obesity epidemic has less to do with our lifestyles than with what we are eating.
‘The key thing that people don’t realize is that throughout history, right until the Seventies, obesity levels never went above 2 per cent of the population in the UK,” she says. Yet by the turn of the millennium, obesity levels were 25 per cent.
What happened? In 1983, the government changed its diet advice. After that, if you look at the graphs, you can see obesity rates taking off like an airplane. You might feel it is coincidence, but to me it is blindingly obvious.
The older dietary advice was simple; foods based on flour and grains were fattening, and sweet foods were most fattening of all.
Mum and Granny told us to eat liver, eggs, sardines and to put butter on our vegetables. The new advice was ‘base your meals on starchy foods’ – the things that we used to know made us fat (rice, pasta, potatoes and bread). That’s a U-turn.
Myth: Starchy carbohydrates should be the main building blocks of our diet
We’ve been told that carbohydrates such as rice, pasta, bread and potatoes should form the bulk of what we eat. The trouble with this, says Zoe Harcombe, is that as carbs are digested, they are broken down into glucose.
This process makes your body produce insulin, in order to deal with the extra glucose. One of insulin’s main roles in the body is fat storage, so whenever you eat carbs, you are switching on your body’s fat-storing mechanism. Whatever carbs you don’t use up as energy will be quickly stored away in the body as fat.
We should get back to doing as nature intended and eat real, unprocessed food, starting with meat, fish, eggs, vegetables and salads.
Myth: Losing weight is about calories in versus calories out
“If only it were that simple,” says Harcombe. People think that if they cut out 500 calories a day, they will lose 1lb a week.
They might at first, but then the body will recognize that it is in a state of starvation and turn down its systems to conserve energy.
‘So you may be putting fewer calories in, but at the same time you will be using up fewer calories to get through the day.
Losing weight is more a question of fat storage and fat utilization. You need the body to move into a fat-burning mode and, to do that, you need to cut down your consumption not of calories, but of carbohydrates.’
Myth: More exercise is a cure for the obesity epidemic
This is standard wisdom: “exercise, we think, will burn calories, lose fat and speed up our metabolism. Think again,” says Harcombe.
If you push yourself into doing extra exercise, it will be counterproductive because you will get hungry – your body will be craving carbohydrate to replenish its lost stores.
If you are trying to control weight, it is so much easier to control what you put into your mouth. Not how much, but what. Then it doesn’t matter what you do or don’t do by way of exercise.
Myth: Fat is bad for us
“Real fat is not bad for us,” says Harcombe. “It’s man-made fats we should be demonizing.” Why do we have this idea that meat is full of saturated fat? In a 100g pork chop, there is 2.3g of unsaturated fat and 1.5g of saturated fat.
Fat is essential for every cell in the body. In Britain [according to the Family Food Survey of 2008], we are deficient in the fat-soluble vitamins A, D and E, which are responsible for healthy eyesight, bone strength, mental health, cancer and blood vessel protection and, therefore, heart health. We need to eat real fat in order for these vital vitamins to be absorbed into the body.
Myth: Saturated fat causes heart disease
Over the past 50 years, we have accepted this as one of the basic nutritional truths. But Zoe Harcombe says: “No research has ever properly proved that eating saturated fat is associated with heart disease, let alone that it causes it.”
Myth: Cholesterol is a dietary enemy
Controversially, Harcombe does not consider ‘high’ cholesterol levels a bad thing!
‘To pick a number – 5 (mmol/l) – and to say everyone should have cholesterol levels no higher than this is like declaring the average height should be 5ft 4in and not 5ft 9in and medicating everyone who doesn’t reach this meaningless number to reduce their height. It really is that horrific.
Ancel Keys, who studied cholesterol extensively in the Fifties, said categorically that cholesterol in food does not have any impact on cholesterol in the blood.
What is abnormal is the amount of carbohydrate we eat, especially refined carbohydrate, and this has been shown to determine triglyceride levels – the part of the cholesterol reading your GP may be most concerned about.
It’s the ultimate irony. We only told people to eat carbs because we demonized fat and, having picked the wrong villain, we are making things worse.
Myth: We should eat more fiber
For three decades, we have crammed fiber into our bodies to help us feel full and keep our digestive systems moving. This is not a good idea, says Harcombe.
The advice to eat more fiber is put forward along with the theory that we need to flush out our digestive systems. But essential minerals are absorbed from food while it is in the intestines, so why do we want to flush everything out? Concentrate on not putting bad foods in.
Myth: You need to eat five portions of fruit and veg a day
“Five-a-day is the most well-known piece of nutritional advice,” says Harcombe.” You’d think it was based on firm evidence of health benefit. Think again!
Five-a-day started as a marketing campaign by 25 fruit and veg companies and the American National Cancer Institute in 1991. There was no evidence for any cancer benefit.
Myth: Fruit and veg are the most nutritious things to eat
Apparently not. Harcombe allows that vegetables are a great addition to the diet – if served in butter to deliver the fat-soluble vitamins they contain – but fructose, the fruit sugar in fruit, goes straight to the liver and is stored as fat.
Fruit is best avoided by those trying to lose weight, says Harcombe, who adds: ‘Vitamins and minerals in animal foods – meat, fish, eggs and dairy products – beat those in fruit hands down.”
Myth: Food advisory bodies give us sound, impartial advice
the organizations we turn to for advice on food are sponsored by the food industry. The British Dietetic Association (BDA), whose members have a monopoly on delivering Department of Health and NHS dietary advice, is sponsored by Danone, the yogurt people, and Abbott Nutrition, which manufactures infant formula and energy bars.
The British Nutrition Foundation, founded in 1967 to ‘deliver authoritative, evidence-based information on food and nutrition in the context of health and lifestyle’, has among its ‘sustaining members’ British Sugar plc, Cadbury, Coca-Cola, J Sainsbury PLC and Kraft Foods.
‘When the food and drink industry is so actively embracing public health advice, isn’t it time to wonder how healthy that advice can be?’ says Harcombe.
Alice Hart-davis, The Daily Mail, UK, Sun, 31 Oct 2010 22:06 CDT