Widepread press coverage of the “demonisation” of sugar as the cause of the obesity epidemic leaves a bitter taste. Not only is it wrong, it is harmful.

There is no doubt that as a nation we consume too much sugar, mostly through the consumption of processed foods, and that this can contribute to an individual’s positive energy balance and lead to weight gain. We could, and should, eat less sugar. To claim, however, that we could remove sugar from our diet completely and that this would solve the obesity problem is both impractical and unreasonable.

Obesity is not new. In the 1980s, 5% of the UK adult population were obese but by 2009 it was 25%, and the consequence to the nation’s health is beyond dispute. The NHS has to deal with an onslaught of type 2 diabetes, heart disease, renal failure and cancer. But obesity is widely recognised as having multifactorial causation. Though perhaps 50% of our individual propensity to weight gain is genetic, our genes have changed little in the past thousand years. What has changed is the environment. The way we live, the way we eat, the jobs we do, and the exercise that we take. The real cause of obesity, therefore, is a combination of excessive energy intake (high-fat, high-sugar foods) and decreased energy expenditure (physical activity). Whie I am supportive of the drive to decrease sugar content in processed foods and to reduce the consumption of unnecessary carbs, to single out sugar and to demonise it in this way calls into question the scientific veracity of the campaign. Linked with claims that “statins” are a huge mistake, and that a high-fat diet can be good for you, ignoring the evidence of perhaps the most intensely researched area in medicine the world has ever seen, further raises questions about their real purpose. Suddenly fat is good, and sugar is bad? I don’t think so.

There is no clear evidence that sugar is directly implicated in causing type 2 diabetes. There is no clear evidence that sugar (fructose) can cause addiction. And to liken sugar to alcohol and tobacco is nonsensical. It is relatively easy to show a direct causation link between tobacco and one quarter of cancer deaths, or alcohol and liver disease. It is not possible to show that same direct link with sugar. Obesity is directly linked to heart disease and cancer but sugar cannot be shown to directly cause obesity. Part of the problem? Undoubtedly, yes. The whole problem? Clearly, no. The comparison to tobacco therefore further devalues the campaign.

Focusing entirely on sugar is harmful as well as misleading. January always sees a plethora of quick-fix diets on the market and many people are seeking new ways to regain control of their health. Many have tried traditional ‘diets’ and failed, and so the lure of gimmicky reductionist diets that focus on one particular food group or exercise activity is likely to attract new disciples. What is most unfortunate is that these new followers of low-carb or ‘no sugar’ diets are also doomed to failure, and will face the consequence of declining health from their obesity over the years.

The real solution to the obesity epidemic is to change the environment in which we live where healthy, low-calorie food is easily accessible and affordable, and where physical activity is easier and more enjoyable than inactivity. And while we wait for these utopic changes to occur (changes which must be led by government, and sadly do not seem likely to happen) each individual must do what they can to help themselves. In my almost 20 years of experience of working with patients to lose weight, the only thing that works is a steady, progressive reduction in sugar and fat intake, and an increase in physical activity, and cementing these new behaviours by tackling the underlying emotional and psychological causes. In short, dealing with food, body and mind simultaneously.

Dr Ian Campbell MBE is a GP and the founder and former chair of the National Obesity Forum