The coming crisis for society caused by millions of people who are seriously overweight will be discussed at a University of Greenwich public lecture on 28 November.
Dr Lucie Pollard, a nutrition expert at the university's School of Science, will be discussing what motivates people to eat, what influences their eating choices and how the nation can tackle obesity.
Dr Pollard says: "There are over 15 million people who are obese in the UK. This is likely to lead to almost half a million more cases of heart disease, and around 700,000 extra cases of diabetes. In addition, thousands of people are also developing cancer as a consequence of their weight.
"Research suggests that we must cut five billion calories a day to tackle this crisis. My talk highlights the individual influences on appetite and proposes strategies for cutting down our intake."
The lecture, Why we eat what we eat: How to lose five billion calories, will examine how eating habits are influenced by physiology, such as hunger and satiety 'signalling', and psychology, including the widespread preference for three meals a day.
"We know that food preferences begin very early, even before we are born, and that many emotional and cultural factors are at play," Dr Pollard adds. "Eating is the most fundamental of all human behaviours, and yet it has one of our most complex behaviour patterns."