At an International Congress on Obesity, in Sydney, Australia, chairman Professor Paul Zimmet has said that obesity is no longer a problem limited to America and other developed countries but has reached the scale of a global epidemic.
The 10th International Congress on Obesity involves over 2,500 health care professionals from around the world, along with over 400 experts who will speak about the issue which is deemed to be the major contributing cause of preventable diseases, such as diabetes and heart disease.
Experts say that overweight and obese people outnumber the undernourished in the world and childhood obesity is now on such a scale that for the first time in history, the human race is facing the possibility of millions of parents outliving their children.
When that generation reaches maturity, say the experts, many nations will be dealing with enormous chronic health problems unless something is done.
According to the World Health Organisation (WHO) there are about 1 billion overweight people in the world of whom 300 million are obese; if this an accurate figure it equates to a world epidemic.
There are 800 million underweight people worldwide.
Obesity is now the greatest contributor to chronic disease.
Obesity among young women has been blamed for a quadrupling in the number of pregnant women with gestational diabetes and experts say young women are in denial about the medical risks of being overweight.
Young women between 18 and 35 are gaining weight more quickly than any other age group, and this is a concern because as many as 50 per cent of women with the condition develop type 2 diabetes within five years.
The condition increases the risk of pregnancy complications, such as having a larger baby, which makes labour and delivery harder.
In Australia alone last year more than 18,500 women were diagnosed with the disease, up from 4286 in 2000.
Professor Kate Steinbeck, the director of obesity services at Sydney's Royal Prince Alfred Hospital, says young women do not see obesity as a medical problem and view weight loss as a concern for older people.
Professor Steinbeck says they are seeing an increase in young women with polycystic ovarian syndrome, gestational diabetes and osteoarthritis in their knees.
Overweight and obesity can lead to coronary heart disease, dyslipidemia (high total cholesterol, high levels of triglycerides), gallbladder disease, hypertension (high blood pressure), osteoarthritis, sleep apnea and respiratory problems, cancers, stroke and type 2 diabetes.