Dr Susan Jebb Chair, UK Association for the Study of Obesity

Dr Jebb: "The miracle is that anyone stays slim"

As UK obesity levels and related health problems are set to soar over the next decade, the BBC's IF television series shows what may happen if we keep getting fatter.

Here, nutritionist Dr Susan Jebb warns if we don't stop overeating the worst is yet to come.

If we don't stop eating by 2010, one third of Britons will be clinically obese and their risk of diabetes will increase more than 10 fold.

Already in the last 20 years obesity in adults has trebled.

In the wake of this tidal wave of obesity and diabetes we will see a rise in the numbers suffering from heart disease and cancer.

Without significant medical advances to enhance treatments for these killer diseases we will see a gradual decline in life expectancies.

If... we don't stop eating is a BBC drama showing what may happen if we keep getting fatter Wednesday, 7 April, 2004, at 2100 BST on BBC Two

Undoubtedly we will also see a decline in the quality of life as people suffer greater levels of ill health. More people will require treatment for high blood pressure, raised cholesterol or angina. More people will suffer from renal failure and osteoarthritis.

Fertility problems, obstetric complications and foetal abnormalities, including neural tube defects, will increase.

The cost for the individual will be high. The cost to the NHS will be crippling.

Less active

Obesity is the long-term consequence of eating more than we need. Over the last 50 years our daily energy needs have declined markedly as lifestyles have changed.

The problem is, we like eating. It is part of our culture, a part of our social lives, part of our family habits and a defining element of our lifestyle

Today there are few manual occupations and the work place is dominated by the use of computers. Daily transport is dominated by the car and our leisure time is dominated by the television, videos, DVDs and computers.

Even basic activities of daily living today make little energy demands. Compare throwing a duvet on the bed each morning to the exertion of sheets, blankets and other bed coverings.

Mobile phones avoid the short walk to the telephone and electrical gadgets have revolutionised household chores.

Even for those who choose to exercise regularly it is difficult to compensate for this underlining decline in activity. Most people are less active than they should be for good health.

Larger portions

Meanwhile it is easier to eat more than ever before. Food is relatively cheap and there is more variety which prevents boredom.

Food is more accessible than ever before with a range of food outlets on the high street, non-food stores stocking a selection of snacks and vending machines populating our public spaces.

Food is served in ever larger portions. Whether we are eating more calories than previously is difficult to estimate as surveys for food habits are notoriously unreliable, but without doubt most people eat more than they need.

Put these two elements together - inadequate activity and excessive food - and you have the recipe for obesity. Weight gain is the default situation, the miracle is that anyone stays slim.

The problem with food is not just confined to obesity. Regardless of the calorie content, we eat too much saturated fat, which increases the risk of heart disease.

Decreasing saturated fat intake by 5% can decrease cholesterol levels and this kind of reduction alone could potentially decrease deaths from coronary heart disease by 4%.

Dr Jebb says we must change the way we eat in the UK

We eat too much salt; an average of 9 grams per day and rising. Decreasing salt intake by just 1 gram could prevent 6,000 deaths per year from strokes and heart attacks.

If we are going to get all the necessary vitamins and minerals in our diet without overdoing the calories we need to increase the nutritional quality of the food we eat.

Culture

Consumption of sugar is way above recommended intakes especially for young people. On average young people get over 16% of their calorie intake from sugar, compared to the recommended intake of just 10%.

Around a quarter is derived from soft drinks and another quarter from confectionery. These are major sources of energy with few essential nutrients.

The problem is, we like eating. It is part of our culture, a part of our social lives, part of our family habits and a defining element of our lifestyle.

The good news is food is not tobacco. No one is asking the nation to give up the food, but we have to change the way we eat, because if we don't stop eating... there is worse still to come.

Dr Jebb is also Head of Nutrition and Health at the Medical Research Council.