Why does it seem like some people can eat whatever they want and stay thin, while others diet their whole lives but never seem to get there? More and more scientific evidence points to the combination of diet and genes and differences between people to explain this phenomenon.
“Nutrigenetics” is the science of how genes influence nutrition, and “nutrigenomics” is how nutrition influences genes. Together, they form the scientific basis for the interaction between genes, food, and health.
While an “obesogenic” environment (one that “generates” obesity) favoring increased food intake and decreased physical activity levels has clearly contributed to increased weight around the globe, not everyone is becoming overweight or obese. On the flip side, not everyone who chooses traditional weight loss methods succeeds in meeting or maintaining their health goals. Further, research findings regarding weight loss and health sometimes seem to contradict each other. This suggests that there are genetic factors interacting with environmental factors to predispose some individuals to obesity and related diseases, and points to the consequences of a diet being dependent on the balance between an individual’s genetic background and their lifestyle practices.
Genetics are thought to account for more than three-fourths of all cases of obesity – but does that really make it a lost cause? The current rise in obesity to epidemic proportions in some modern countries – as well as findings of obesity-related disease risk factors in normal-weight people – has highlighted the role of environmental factors. This gene-environment interaction is not only important in determining an individual’s susceptibility to obesity but can also influence the outcome of weight-loss programs and weight-management strategies in overweight and obese subjects. Everyone is built a little differently, and therefore the response to certain diets or exercise can vary significantly. More and more scientific evidence is pointing to the combination of diet and genes and differences between people, and the possibilities of working with diet according to one’s genes to find a match made in health heaven.
The ability to adapt to one’s immediate environment, including changes in diet and physical activity level, is key to maintenance of overall health. Several processes and mechanisms have been suggested to be involved in the ability to adapt, including regulation of blood sugar by insulin, control of inflammation and oxidative stress, and optimization of immune function.
Genes control these mechanisms, and affect key related factors such as metabolic rate (how fast you burn energy or calories), how the body burns and stores fat, and what happens to fat and sugar in your bloodstream. Fortunately, some of the same key elements affecting one also affect the other – so when you optimize your weight loss and maintenance, you are also optimizing your health potential.
Certain nutrients can impact adaptation, and their excess or insufficiency can have significant implications. According to Elaine Trujillo, nutritionist at National Institutes of Health (NIH), diet and dietary components can alter the risk of disease development by modulating multiple processes involved with onset, incidence, progression, and/or severity. Food components can act on genetic activity, either directly or indirectly, and diet could influence that activity, for better or for worse.
Scientists are working to fine-tune methods to provide personalized diet and exercise programs that are uniquely suited to an individual’s genetic profile. In the meantime, there have been a number of studies published that offer a starting point. For example, while it was long observed that substituting total fat with carbohydrates resulted in weight loss in individuals with previously high fat intake, later research revealed that many people with altered metabolism of insulin and related hormones may require lower levels of carbohydrates to optimize fat metabolism, and higher levels of protein to control appetite. Similarly, while varied intake of fruits and vegetables is recommended for everyone, different metabolic profiles suggest the need for greater emphasis on one or another type of fruit. For example, recent research has revealed that anthocyanins (i.e. from berry type fruits and purple vegetables) have differing potent activity against adipocytes (fat cells), depending on the specific composition of the fat cell. Such information could be tapped for the prevention of weight gain and disease risks and/or attainment of beneficial weight loss and maintenance.
The future will yield wider use of simple genetic testing in nutrition clinics to determine the best course for the health-conscious dieter. In the meantime, family medical and weight histories, conventional blood tests related to sugar, fats, and inflammation, along with signs and signals we get from trial-and-error attempts at dieting, reveal priceless information. Given the right information and the right guidance, the optimal plan for you to obtain and maintain optimal weight and health is already within reach.
Hi, EstesLucy2. Hypothyroidism, if uncorrected by thyroid replacement therapy, generally results in a slowed metabolism, which makes it challenging to attain and maintain a healthy weight. There is no known diet to correct the condition, but a nutritional plan based on maximizing metabolism from every other aspect is a good complement to the medication. To avoid interfering with its activity, it is recommended to avoid the following within an hour of taking it: walnuts, soy (especially soybean flour), cottonseed meal, or iron, iodine, or calcium supplements or multivitamin/mineral products containing them.
I have a thyroid problem, Now I am hypothyroid, how will this affect my diet?, what changes should I make in my current diet?