I don't believe that anyone chooses to be fat. The Gallup International survey of 57,000 adults revealed that health is what mattered most in life, followed by a happy family environment. So how can this be reconciled with the statistic that 60% of UK adults and one in three children are overweight or obese?

It is partly because a fundamental misunderstanding among the public – and the scientific community – has interfered with our collective ability to curb this epidemic. The belief that we make our food choices deliberately, and that they reflect our true desires, sustains the status quo and obscures the reality that decisions about the food we consume are often difficult to control.

As Professor Theresa Marteau, director of the behaviour and health research unit at the University of Cambridge points out: "We are heavily influenced by automatic behaviours… where the desire for instant gratification far outweighs less assured and more distant rewards."

It is this instinctive behaviour that has been exploited by a food industry that has handsomely profited from ensuring cheap junk food is available to anyone, anywhere, at any time. The further manipulations have been rightly put under scrutiny in recent months, with the exposure of hidden sugars in foods not normally associated as being junk, such as salad dressings and even "low fat" or "healthy" cereals.

A group of interested parties, including myself, launched Action on Sugar this year. Our aim is to press the food industry into reducing added sugar in processed foods. We are not telling you – despite some of the screaming "sugar is toxic" headlines – that bananas and oranges are evil.

The food industry's classic response is to say that the ingredients are listed on the label, knowing full well that many consumers will purchase a food item based upon the way it's promoted, not its nutritional content. The fact that many products in a single portion come close to, if not exceed, the recent World Health Organisation limits of six teaspoons of non-milk extrinsic sugar (NMES) is as clear an indication as any that this issue is way beyond one of simple personal responsibility. Regulation to protect consumers and children is clearly needed.

NMES includes any sugar added to food in processing, as well as fruit juice and smoothies. Fruit juice lacks the fibre of whole fruit, which slows the absorption of sugar into the blood stream and makes you feel full more easily. You can easily down a glass of juice made up from six apples and still feel hungry, but try eating more than three whole apples and you'll struggle.

In addition to overwhelming scientific consensus that added sugar is a source of unnecessary calories, there is mounting evidence that the effects of excess consumption are independent of body weight. A study published in JAMA Internal Medicine last month revealed that those who consume more than 25% of calories from added sugar trebled their risk of cardiovascular death compared with those who consumed less than 10% from added sugar, even among the non-obese.

However, the industry remains in denial. On BBC Newsnight recently, the president of Coca-Cola Europe said his company's nine sugar-lump laden drink had the same number of calories as half a croissant or a cappuccino. Coca-Cola says that it's OK to consume its "happy" calories as long as you exercise, but this is not in keeping with independent scientific evidence. It matters where the calories are coming from.

The erroneous message that has promoted calorie restriction over good nutrition has proved to be the lottery win for diet companies. In the United States, the weight-loss industry generates a staggering $58bn in revenue annually, despite long-term studies revealing that the majority of individuals regain virtually all of the weight lost during treatment, irrespective of whether they maintain their diet or exercise programme. And such fad dieting that encourages rapid weight loss followed by regain is detrimental to health.

With all the attention on sugar, we mustn't neglect the other dietary villains. The excess consumption of refined carbohydrates found in white bread, pizza bases, burger buns and chips, combined with the excess salt and trans-fats in processed meat, continues to have awful consequences. On Friday, a study revealed that greater access to takeaway shops was associated with a greater body mass index and higher odds of obesity.

The traditional Greek/Mediterranean diet of oily fish, extra virgin olive oil, nuts, vegetables and yes, plenty of whole fruit (and, happily, a moderate intake of red wine) has the strongest evidence base for reducing heart attacks, strokes, dementia and cancer. Such a diet, also low in refined carbohydrates, may even be the best for athletic performance, according to one of the most respected sports medicine scientists in the world, Professor Timothy Noakes, of South Africa. Prof Noakes discusses its merits in Cereal Killers, a documentary that has its UK premiere in London tomorrow. It has been adopted by the Australian cricket team under the guidance of their physician, Dr Peter Brukner, and it clearly hasn't done them much harm in their recent performances.

Meanwhile, Big Food continues to peddle pathology with impunity, spending billions targeting children with junk food advertisements and even co-opting "respected" scientific bodies. Last week, Professor Ian McDonald, chair of the UK's Scientific Advisory Committee on nutrition, who has admitted to receiving substantial amounts in research funding from Coca-Cola and Mars, declared that his board will ignore the new guidance from the WHO on sugar limits. How he can continue in his current role when his credibility has been so badly compromised is beyond me.

When I met health secretary Jeremy Hunt a few weeks ago, he said there was no silver bullet to tackling the obesity epidemic and wanted a plan of action. But he already has one. It's been just over a year since Britain's doctors submitted a 10-point plan, following a one-year review of the evidence on policies to tackle the obesity epidemic. These included a tax on sugary drinks, banning junk food advertising to children, restrictions on fast food outlets near schools and compulsory nutritional standards in hospitals.

Not a single proposal has been implemented. Political ideology continues to trump scientific evidence and the interests of Big Food continue to take precedence over our children's health. According to Britain's chief medical officer, Dame Sally Davies, our continued failure to act may result in the first generation of children that will be outlived by their parents. That is a truly chilling prospect that can no longer be ignored.

Aseem Malhotra is a cardiologist and science director of Action on Sugar