He announced this decision in the light of recent findings by Prof Klim McPherson of Oxford University and Tim Marsh of the National Heart Foundation that obesity may afflict more than half of the population within 25 years.
The researchers have warned that 86 per cent of men are likely to be overweight in 15 years, and 70 per cent of women within 20 years.
They have also warned that the cost of fighting various problems arising out of obesity—such as diabetes, stokes, heart disease, and the loss of earnings by those who are too heavy to work—may reach 45 billion pounds a year by 2050.
The researchers attribute part of the problem to artery-clogging trans fats.
Johnson compared the problem of obesity to global warming, and insisted that there was need to consider the introduction of stricter measures to check trans fats in food products.
"I will be asking the Food Standards Agency to conduct an immediate investigation into the evidence in this area to see if there is anything more we should be asking the food industry to do," the Telegraph quoted him as saying.
"For the first time, we are clear about the magnitude of the problem: we are facing a potential crisis on the scale of climate change and it is in everybody's interest to turn things round," he added.
Johnson said that the Government could not overcome the trouble alone, and urged individuals should also take the responsibility of finding its solution.
"It cannot be tackled by Government action alone. We have made progress with improved physical activity levels at school, healthier school food for children, clearer food labelling and tougher restrictions on advertising foods high in fat and sugar to children. But we know that we need to go further and faster," he said.