FTO Gene: The Most Important Gene For Diet & Fitness

Watch: Top 10 Amazing Facts About the FTO Gene

Understanding our genetic makeup can offer valuable insights into various aspects of our health, including our predisposition to weight gain and obesity. One gene that has gained considerable attention in this area is the FTO gene.

What is the FTO Gene?

The FTO gene, short for the ‘Fat mass and obesity-associated gene’, is a gene that is associated with fat mass, body weight, and the risk of obesity. It’s found in every body cell and plays a significant role in managing energy use and storage in the body.

What Does the FTO Gene Do?

The FTO gene provides instructions for creating an enzyme (also called FTO) that is involved in controlling how your body uses and stores energy.

Think of your body like a car. The food you eat is the fuel that powers your body, just like gasoline powers a car. Just as a car’s engine controls how it uses fuel, the FTO enzyme helps control how your body uses the food you eat.

For example, when you eat food, your body breaks it down into smaller parts, including a type of sugar called glucose. This glucose is then used by your body’s cells for energy. The FTO gene plays a role in controlling this process.

Specifically, it influences two key aspects of this ‘energy management system:

1. Appetite Regulation: It helps regulate your feelings of hunger and fullness. If the FTO gene isn’t functioning properly, you might not feel full after eating, leading you to eat more than you need.
2. Metabolism Regulation: It also helps regulate your metabolism, which is the process your body uses to convert food into energy. Changes in the FTO gene can alter your metabolic rate, potentially making you burn fewer calories when at rest, leading to weight gain over time if not balanced by physical activity and a controlled diet.

So, the FTO gene helps manage how your body uses and stores the energy it gets from food, influencing your food intake and how efficiently you burn calories.

How Does the FTO Gene Cause Obesity?

The FTO gene’s connection to obesity is largely a result of how it influences two critical aspects of our body’s energy balance: appetite regulation and metabolism.

Appetite Regulation

The FTO gene plays a role in managing your feelings of hunger and fullness. Some people have variations in their FTO gene that affect the gene’s function, causing them to feel hungry more often. This can lead to increased food intake, especially high-calorie foods often associated with weight gain. If the extra calories consumed aren’t offset by physical activity, they get stored in the body as fat, contributing to weight gain and potentially leading to obesity.

For example, studies have found that individuals carrying certain FTO gene variants prefer high-calorie, energy-dense foods. They also tend to feel less satiated after meals, which can contribute to overeating.

Metabolism Regulation

The FTO gene also influences your metabolic rate, which is the speed at which your body burns calories for energy. Variations in the FTO gene can change your metabolic rate, causing your body to burn fewer calories than it normally would.

If your body isn’t burning calories as efficiently, it means more calories are stored as fat. Over time, this can lead to weight gain and an increased risk of obesity, especially if combined with a high-calorie diet and low physical activity levels.

It’s also worth noting that the influence of the FTO gene is not deterministic. In other words, having these variations in your FTO gene doesn’t guarantee you’ll become obese, but it does mean you might have a higher predisposition towards obesity. Environmental factors, like diet and physical activity, play a crucial role and can help mitigate this genetic risk.

Main FTO Gene Variants

Several variants within the FTO gene are associated with body weight and obesity risk. Here are the most commonly studied ones:

rs9939609

The rs9939609 variant is the most well-studied FTO gene variant. Individuals with the AA or AT genotype are associated with a higher risk of obesity and tend to have a higher body mass index (BMI) compared to those with the TT genotype.

rs1421085

The rs1421085 variant is another significant FTO gene variant associated with obesity risk. Individuals with the CC genotype have been found to have a higher risk of obesity and tend to have a higher BMI than those with the TT or TC genotype.

rs17817449

The rs17817449 variant is also associated with obesity risk. Those with the GG genotype tend to have a higher risk of obesity and BMI than those with the TT or GT genotype.

SNP Table

Gene	SNP	Risk Allele	Description
FTO	rs9939609	A	Those with the AA or AT genotype have a higher risk of obesity and tend to have a higher BMI.
FTO	rs1421085	C	Individuals with the CC genotype have a higher risk of obesity and tend to have a higher BMI.
FTO	rs17817449	G	Those with the GG genotype tend to have a higher risk of obesity and higher BMI.

Genetic variants don’t guarantee you will or won’t become obese – they suggest a predisposition. Many factors, including diet, physical activity, sleep, stress, and other genetic factors, also play important roles in weight management.

Latest Scientific Findings on the FTO Gene

The FTO gene is one of the most studied genes in obesity genetics due to its significant impact on body weight regulation. Here are some of the latest scientific findings on the FTO gene:

The FTO Gene and Appetite Regulation

Research continues to underscore the FTO gene’s role in regulating appetite. One groundbreaking study found that people with certain variants in the FTO gene had higher levels of the hormone ghrelin in their blood. Ghrelin, often dubbed the ‘hunger hormone’, signals to your brain that it’s time to eat. As a result, people with these FTO variants may feel hungrier sooner after meals, which could lead to overeating and weight gain.

The FTO Gene and Dietary Interactions

Some recent studies suggest that the FTO gene may interact with dietary habits to influence weight. For example, research has shown that a high-protein diet may help mitigate the obesity-related effects of certain FTO variants. This could be because protein is more satiating than other macronutrients, which might help counteract the increased hunger associated with these FTO variants.

The FTO Gene and Physical Activity

Physical activity plays a crucial role in managing body weight and mitigating genetic predispositions to obesity. A recent meta-analysis of several studies confirmed that physical activity could lessen the effect of FTO on obesity risk. This suggests that while certain FTO variants may predispose to obesity, maintaining a physically active lifestyle can help offset this genetic risk.

The FTO Gene and Bariatric Surgery Outcomes

Some recent studies have explored how the FTO gene might influence the outcomes of bariatric surgery, a common treatment for severe obesity. For example, one study found that individuals with certain FTO variants lost more weight after bariatric surgery. However, more research is needed to understand these relationships fully.

Section Summary

These findings provide valuable insights into how the FTO gene contributes to obesity and point to potential strategies for managing weight and mitigating genetic risks. As always, it’s important to remember that genes are just one piece of the puzzle regarding body weight, and various environmental factors like diet, physical activity, and lifestyle habits also play a critical role.

Summary

What is the FTO gene? The FTO gene, or ‘Fat mass and obesity-associated gene’, is a gene associated with body weight and the risk of obesity.

How does the FTO gene cause obesity? Certain variants of the FTO gene can increase hunger and food intake, leading to weight gain and potentially obesity if not balanced by physical activity.

Can lifestyle changes help if I have the FTO risk variant? Yes, regular physical activity and a diet high in protein and low in processed foods can help manage the impact of the FTO gene on obesity risk.

References

1. Frayling TM, Timpson NJ, Weedon MN, et al. A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity. Science. 2007;316(5826):889-894.
2. Tanofsky-Kraff M, Han JC, Anandalingam K, et al. The FTO gene rs9939609 obesity-risk allele and loss of control over eating. Am J Clin Nutr. 2009;90(6):1483-1488.
3. Speakman JR, Rance KA, Johnstone AM. Polymorphisms of the FTO gene are associated with variation in energy intake, but not energy expenditure. Obesity (Silver Spring). 2008;16(8):1961-1965.
4. Timpson NJ, Emmett PM, Frayling TM, et al. The fat mass- and obesity-associated locus and dietary intake in children. Am J Clin Nutr. 2008;88(4):971-978.
5. Cecil JE, Tavendale R, Watt P, Hetherington MM, Palmer CN. An obesity-associated FTO gene variant and increased energy intake in children. N Engl J Med. 2008;359(24):2558-2566.