Every fast food meal bumps up BMI, study says

SALT LAKE CITY — Whether people are rich or poor, odds are pretty good that they have eaten fast food within the past week if they live in the U.S. And while doctors and researchers have long-touted the harmful effects of eating fast food, a new study says shows exactly how much fatter a person gets with each fast food meal he or she eats.

Still want fries with that?

The study, conducted by U.S. and Irish researchers, showed that for every fast food transaction, the average BMI went up by 0.03.

“The take-home message is that, although free-market policies are not to be demonized, it appears quite clear that in order to fight the obesity epidemic, a stronger role of government intervention is necessary,” head researcher Dr. Roberto De Vogli of the department of Public Health Sciences at the University of California, Davis told TODAY.com.

Using Body Mass Index can be considered somewhat controversial as some studies have shown BMI isn’t always the most accurate measure of health.

A woman who is 5-feet-6 inches and weighs 154 pounds has a BMI of 24.9, the highest acceptable weight level for a healthy woman of that height. But if she were to weight one more pound, she would be considered overweight. According to the Centers for Disease Control and Prevention website, BMI is relatively accurate and has a high correlation with body fat, but it can vary by sex, race and age.

De Vogli and his team looked at data from 25 high-income countries from 1999 – 2008 and compared fast-food transactions to the average BMI.

“While the average number of annual fast food transactions per capita increased from 26.61 to 32.76, average BMI increased from 25.8 to 26.4,” they said in an article on the Bulletin of the World Health Organization.

The study took many factors into account, including amount of exercise, if a person lived in the city or out, age and income level. The wealthier countries had higher levels of people eating out. People who lived in the suburbs also tend to drive more than walk, and De Vogli told TODAY.com the study also took that into account. They didn’t, however, look at how much other junk food people ate during the week.

“To be completely fair to the fast-food industry, highly processed food, all those types of processed products are also higher where there is higher fast-food consumption,” De Vogli told NBC News. “So we will look at that next.”

The study also found that the biggest correlations between fast food transactions and BMI increase were associated with the lowest levels of food regulation. Canada, New Zealand, Australia and Ireland all had the highest levels of fast food transactions and BMI.

The countries with the highest food and market regulations had the lowest fast food transactions and BMI, including Greece, Italy and the Netherlands.

“The more aggressive market-liberalized countries have a higher consumption of fast food,” he said. “Trade protection might not always be a good thing, but our study found consumption of fast food was much lower in countries that have higher regulation.”

The study also looked at data from United Nations Food and Agricultural Organization and found that, on average, people ate 3,432 calories per day in 2002 and 3,437 in 2008 and their fast food intake increased each year between 1999 and 2008.

It also showed that the people were, on average, overweight and have been for the past 15 years.

Dr. Francesco Branca, director of the Department of Nutrition for Health and Development at WHO, told NBC News that this study shows that public policies need to start to address the obesity epidemic around the world.

“Policies targeting food and nutrition are needed across several sectors including agriculture, industry, health, social welfare and education,” Branca said.

In order to lower their BMI, people should stay away from fast food and try to eat locally grown produce as much as they can, De Vogli said.

Public policies protecting small farmers, much like the farm bill that passed in the Senate Tuesday that will help insure crops, will help people have more access to locally grown food. The Food and Drug Administration is also in the process of banning trans fats from foods.

Calculate BMI on the CDC website here.