Fried foods are bad for you. We all know that. Many have observed, however, that the impact of these foods tends to vary from person to person; some put on weight relatively quickly, whereas others appear almost immune to their fattening effects. New research suggests that the reason for these vastly divergent reactions might have to do with our genes.
In study released in March 2014, researchers from the Harvard School of Public Health identified ten obesity risk genes that influence how the body handles fried foods. Published in the British Medical Journal, this report based its findings on data from nearly 30,000 adult subjects. Each adult’s genetic risk for obesity was taken into account; the researchers determined this information by recording the presence (or lack thereof) of 32 distinct genes.
Some of the results from the study were hardly surprising; for example, subjects that consumed fried foods on a more frequent basis had a greater risk of weight gain. Likewise, adults with a higher BMIs (body mass indexes) were found to be carrying a larger amount of “obesity” genes. What was especially noteworthy was that those with the highest BMIs and obesity risks possessed both risk factors; that is, a high number of fat genes and a tendency to eat fried foods. Essentially, the report concluded that these individuals were exacerbating a preexisting problem through poor dietary choices.
A prior report, authored by the same group of researchers, unearthed a similar relationship between weight gain and soda. Specifically, subjects with all ten obesity genes increased their BMI by 1.8 points by drinking one soda per day. Conversely, those with none of these genes experciend slightly more than half the bump in BMI when consuming the same amount of soda. The study was published in the October 11, 2012 issue of the New England Journal of Medicine.
Genes and Fatty Food Cravings
Aside from being more susceptible to the effects of fried foods, there is also evidence that some people are genetically hardwired to desire such fare. Or, to be more accurate, having certain genes might trigger cravings for fatty foods in general. This was the opinion of a collaborative study authored by researchers from Penn State University, Cornell University, Columbia University and Rutgers University.
Funded by the National Institutes of Health, this report identified a gene known as CD36 as the culprit behind unhealthy food preferences. A total of 317 African-American adults participated in the study; the researchers chose this ethnic group due to their susceptibility to obesity. Compared to those without it, people with certain forms of the CD36 gene were found to have stronger desires for fatty foods. The presence of this gene was determined via saliva samples.
In order to gauge the subjects’ fatty food preferences, each participant was given a salad coated with a dressing. Included in these dressings were varying levels of canola oil. Commonly used for cooking food, canola oil contains a significant amount of long-chain fatty acids. Upon tasting the salads, the subjects were asked to rate the canola oil’s creaminess, fat content and oiliness. The available choices for each category ranged from “extremely low” to “extremely high.”
In addition to the salad test, each adult was given a questionnaire regarding their opinions on numerous items. Foods such as sour cream, mayonnaise, cheese, hot dogs, bacon, fried chicken, French fries, cake, chips, cookies and doughnuts were included on the questionnaire. The subjects were asked to assign each item a ranking; options ranged from “dislike extremely” to “like extremely.”
Compared to other subjects, the researchers found that those with the “AA” form of the CD36 gene assigned higher creaminess levels to the dressings, regardless of dressings’ actual fat content. Furthermore, those with the AA variant of the CD36 gene had the strongest preferences for half-and-half, salad dressings, olive oil and other popular cooking oils. The research team published their findings in the May 2012 issue of the journal Obesity.
Eating a Lot, But Staying Thin
That brings us to the to the flip side of the coin – people who seem impervious to weight gain, no matter what they eat. Once again, the answer may boil down to genetics. According to a 2014 study, rats with a genetic tendency towards leanness reacted differently to physical activity than other rats. The muscles of these rats burned more calories during exercise than rats with “fat” genes. This could mean than thin people may have their muscles to thank for their perpetual skinniness. The study appeared in the March 15th, 2014 issue of the American Journal of Physiology-Endocrinology and Metabolism.
Obesity is often viewed as a completely self-inflicted problem. While the blueprint for staying thin generally hinges on proper diet and exercise, it appears our genes may also have a say in the size of our waistlines.