by Mohit Joshi London, June 30: Focusing on reducing how much and how often people eat could help tackle obesity, experts have said. A recent study revealed that increases in the number of eating occasions and portion size are responsible for tipping the scale for many Americans. Obesity levels have risen sharply in many Western countries since the 1970s. In the US, where the study was carried out, a third of all adults - more than 72 million people - are now categorized as obese. A team from the University of North Carolina analysed data from food surveys carried out in the seventies, eighties, nineties and the last decade. The surveys record all food and drink a person consumes over a 24-hour period. The average daily energy intake of a US citizen increased from 1,803 kcal in 1977-78 to 2,374 kcal in 2003-06. In the last decade of the study alone, the average daily calorie intake went up by 229 kcal. Several factors are involved in energy intake - the number of calories ...