Britain's top GP today launches a scathing attack on widespread reckless public behaviour towards food, alcohol and cigarettes, which he claims is causing growing levels of disease and early death.

In a dramatic intervention in the public health debate, Professor Steve Field criticises parents, mothers-to-be, the very overweight, smokers and drinkers for damaging their own health, or their children's, through irresponsible actions.

Writing in today's Observer, Field, chairman of the Royal College of General Practitioners, backs the controversial call by Andrew Lansley, the health secretary, for Britons to take more responsibility for protecting their health. "The truth is that too many of us neglect our health, and this is leading to increasing levels of illness and early death," Field writes. Soaring levels of diabetes, much of it caused by obesity, and the medical consequences of heavy drinking, which are affecting ever-younger people, illustrate this widespread failure, he adds.

Discussion of the harmful medical consequences of ill-advised personal behaviour is curtailed because of its sensitivity, Field argues. "Too many people do not face up to the hard facts, as they perceive them to be an attack aimed, in particular, at the poorer members of society. But it is impossible to argue on medical or ethical grounds that such behaviour is acceptable."

While arguing for health prevention to become an individual duty and start at home, Field makes it clear that he does not want people to be left to make lifestyle changes on their own or to see personal responsibility as a total solution. Those who seek to alter their behaviour need continuing NHS and government help, he adds. "So please don't take offence if we [GPs] tell you to lose weight or stop smoking or drinking. You need to face facts and take responsibility. Support is out there and it could save your life – and save the NHS a fortune."

Anne Milton, the public health minister, said greater personal responsibility was vital. Many senior doctors also agreed, but stressed that government action was needed to help create a climate in which people could swap healthy for unhealthy behaviour, such as by monitoring big food companies. Lansley has alarmed senior doctors by saying the coalition will use much less regulation than Labour did to tackle problems such as obesity and smoking.

GPs seek to help people live healthy lives "but every day we are confronted by the harm caused by smoking, excessive alcohol consumption and the 'tsunami' of obesity", adds Field, the leader of the country's 40,000 GPs.

Irresponsible parents are damaging their children's health by smoking around them, feeding them unhealthy food and failing to act as good role models, he says. Mothers and fathers who smoke in cars carrying their offspring – who Field says "are committing a form of child abuse" – and at home in front of their children kill more young people than do accidental injuries.

Parents who give their children unhealthy food, or serve them large portions are storing up huge problems for them, says Field. "Unless parents exert more control over their children's diets, they are risking a lifetime of health problems, and even premature death – death before their parents, which is almost too sad to contemplate," he adds.

Parents' failure to safeguard their children from sunburn and using sunbeds can also lead to them developing skin cancer, he argues. Mothers who smoke while pregnant risk causing their child's death through cot death syndrome, asthma, lung infections or house fires. Would-be mothers and women who are already expecting need to control their weight because maternal obesity can harm the mother or her baby.

Instead of becoming obese and then asking the NHS to provide liposuction or gastric bands, "it would be better if people didn't become fat in the first place", by eating better and exercising more.

Agreeing with Field, Milton said: "We need a new public health movement, owned by everyone, for everyone's benefit. A movement that transforms the way in which the public's health is improved, but also revolutionises the way we think about it. As Field points out, personal responsibility is a key part of this."

However, Milton added: "The government recognises that it cannot force people into behaving in a certain way. But we can help people make informed decisions and ensure that they are enabled and supported to make healthy choices."

Professor Terence Stephenson, president of the Royal College of Paediatrics and Child Health, agreed some parents let down their children. "Of course paediatricians agree that people should take responsibility for their own lives. But young children cannot do that. What they eat and the environment they live in are determined by their parents. There is a role for society to protect young children from promotion of unhealthy foods and passive smoking. Would all parents strap young children into a car seat if it was left to choice rather than law?"

He urged a twin-track approach of exhorting parents to care for children well but society also intervening to help by, for example, limiting advertising of unhealthy foods.

Dr John Middleton, vice-president of the UK Faculty of Public Health, said: "A significant amount of ill-health is due to people's lack of personal responsibility. The NHS would have fewer burdens on it if people were more physically active, cut their alcohol consumption and ate a lower-fat, lower-sugar diet. The government and the NHS cannot do everything. But someone trying to give up smoking will find it easier if they get counselling and nicotine replacement therapy on the NHS, for instance."

The government had a key role to play in promoting health, as shown by its crackdown on smoking and its fluoridisation of water supplies, said Professor Dinesh Bhugra, president of the Royal College of Psychiatrists. People who insisted on smoking despite all the warnings about it should retain their freedom to do so, he added.

But Tam Fry, National Obesity Forum spokesman, suggested Field was being naïve. "If Professor Field wants a world where everyone assumes personal responsibility, he is living a dream. He appears to have forgotten the 35-40% of our population who live in the same obesogenic environment as he does but simply can't cope with it or have long since given up the unequal struggle. They are the people who are quite unequipped to resist the 24/24 battering of junk food promotion and are easy prey for the marketing men."

However, "certainly the 40% of women entering pregnancy either overweight or obese do so simply because they have never had role model lessons in parenting from either their own mothers or health professionals", Fry added.