A lack of exercise rather than diet is behind Northern Ireland's expanding waistlines, according to a University of Ulster lecturer.
Waistlines grow as exercise falls
Dr Marie Murphy says our calorie intake has decreased over the last century, but we do less physical work and travel everywhere by vehicle.
Dr Murphy, a senior lecturer in exercise physiology, said lifestyles must change to tackle obesity.
She said most people should "exercise moderately" for 30-45 minutes a day.
Dr Murphy said that people become overweight or obese when there is an imbalance between energy intake and energy expenditure.
"Data from National Food Surveys suggest that our total daily energy intake has declined from the 1970s," she said.
"The rise in obesity in our society is attributable, in part, to our low levels of physical activity, which reduce our energy needs."
She pointed out that only 20% of people are now employed in manual jobs; watching television and using computers or videos are now the most popular leisure pursuits.
A large proportion of car journeys in Northern Ireland are under three miles in length, a distance commonly walked by our grandparents, Dr Murphy says.
She said children are much more sedentary because many parents prefer young children to be in the home rather than outside, because of a perception that the modern world is more dangerous.
The lecturer said moderate exercise did not have to be vigorous, but could include walking, gardening, taking the stairs, and active play with children.