Study questions association between junk food and obesity, points finger at total calories consumed

09-Nov-2015 - Last updated on 09-Nov-2015 at 14:03 GMT

Source: Cornell University Food & Brand Lab

Demonizing unhealthy food as the primary cause of weight gain may be off-track, suggest researchers who found consumption of fast food, sweets and salty snacks alone may not be the harbinger of obesity it often is made out to be.

“To lose weight, patients are commonly told to reduce or eliminate their intake of indulgent foods,” but “interestingly, for the majority of patients – including those who are overweight (BMI up to 44.8) – there was no relationship between their intake of these foods and their BMI,” according to a recently published study in Obesity, Science and Practice.

In fact, the correlation between body mass index and eating “these bedeviled foods” was mildly negative, much to the surprise of the co-researchers and co-founders of Cornell University Food & Brand Lab David Just and Brian Wansink.

Specifically, they found people with BMIs in the normal range ate 1.3 sweet snacks over two days, which is more than the 1.2 snacks consumed by overweight participants, and the 1.1 consumed by obese and morbidly obese participants.

They found similar results for salty snacks, which people with normal BMI ate 1.1 times over two days compared to those who were obese who ate 1 and those who were overweight or morbidly obese who ate 0.9 salty snacks.

The findings are based on data from the 2007-2008 Centers for Disease Control’s National Household and Nutrition Examination Survey, which also showed no significant variation between BMI and eating French fries, full-calorie soft drinks or desserts.

So, what is fueling the increase in obesity, if sweets and salty snacks are not to blame? Just and Wansink say the bulk of the increase in calorie intake as obesity rates rose since the 1970s came from grains and fats.

On average, Americans consumed about 409 calories from grains and 346 from added fats in 1970, but 40 years later calories consumed from grains has climbed 42% to 582 and 70% for added fats to 589. Calories from added sugar have also increased from 333 to 367 as have calories from meat, eggs, nuts, dairy and fruit. Calories from vegetables, however, dropped slightly from 129 to125.

This all adds up to a 25% increase in overall daily caloric consumption from 2039 to 2544, according to data from the US Department of Agriculture cited by the Food & Brand Lab.

The study also found that participants with higher BMI ate fewer fruits and vegetables than those who were in the normal weight range.

“The results of this paper suggest that the frequency of use of problem foods is not a strong indicator of healthy weight or diet and reduction may not be sufficient for weight loss without additional lifestyle changes,” the study argues.

Rather, it adds: “Reducing the calories of food eaten at home and the frequency of snacking may be more successful dieting advice for the majority of individuals.”

In particular, the researchers recommend consumers be conscious of how much added fat from salad dressings, cooking oils and cream they eat, as well as how much flour from baked goods and cereals they consume.