‘Personalised nutrition’ is unquestionably one of the breakthrough concepts of the 21st century for the optimisation of health, fitness and fat loss. Good trainers, coaches and nutritionists have always known two different people can have vastly different responses to the same diet or supplement regime—no good coach puts all their clients on the same diet. Traditionally, it is best practice to ask detailed questions about a client’s current and past diet history, family history, weight fluctuations and health. This information—combined with some closely-monitored, trial-and-error, dietary manipulations—works well when practised by an experienced professional. The problem of course, is it can take months and even years of making these dietary modifications before an optimum diet is designed. Also, most trainers and coaches do not possess the requisite knowledge of nutrition to competently achieve the best outcomes.
Today, the personalised nutrition process can be substantially streamlined by the rapidly-emerging technology of genetics. As with the risk of disease and how people respond to different drugs and exercise programs, it has become clear that people’s body weight and body fat levels are substantially controlled by genetics. Researchers estimate the involvement of genetic factors in the development of obesity is between 64 and 84 percent! Large studies of adopted children have shown despite their shared environment with their adoptive parents, their body composition more closely resembles that of their birth parents. This kind of data leaves little doubt a large part of the solution to the obesity epidemic—and improved fitness, muscle mass, health, etc.—lies in the application of individualised, genetic-based treatments.
Of course, the tried-and-true methods above are still essential but thousands of studies are now coming out every year, suggesting associations between different gene variations and the way those variations affect responses to different foods and supplements. There is still much research to be done and most human traits that determine how we respond to different diets are affected by more than one gene—often dozens or hundreds—but there are currently some strong associations, which can be used to make better dietary decisions.
For example, one of the most useful things our genetic profile can tell us is whether we are likely to respond to reduced-carbohydrate diets. Research shows certain people respond better to lower-carb diets, while other people simply need to reduce calories. Currently, there are several gene variations which can have a two- to three-fold influence on insulin function. If an individual has several of the ‘poor’ insulin function genes, they are likely to do much better on lower-carb, lower-glycaemic diets. If their gene variations predict good insulin function, they don’t have to worry about specifically cutting carbs.
Another gene, which affects obesity risk and is affected by dietary intake, is the FTO gene. FitnessGenes Ltd has participated in researching this gene in collaboration with Loughborough University and University College London. Studies show high saturated fat intake and low polyunsaturated fat intake seem to be triggers that predispose those with certain FTO variations to obesity. They are also likely to respond positively to higher-protein diets. Other genes strongly predict whether caffeine will improve your performance or whether you are likely to be intolerant to lactose and of course there are many other possibilities.
So, if personalised nutrition isn’t on your radar, it almost certainly will be soon!
Mark Gilbert is co-founder of FitnessGenes Ltd, who provide genetically-based testing and recommendations. Mark is also Vice Chair of the European Specialist Sports Nutrition Alliance (ESSNA).