Metabolism describes the way our body controls intake, storage & utilization of nutrients. Our body’s metabolism is an intricate system that involves stomach, brain, heart, pancreas, kidney, brown fat, white fat & many more tissue types. We feel hungry for a lot of reasons. The biggest one occurs when our body detects lack of readily available nutrients. We need energy to power our brain, heart, skin & every other tissue in our body & we get that energy from the food we eat. However, it is not efficient to eat only when we need energy. Our body has to extract extra important nutrients from the food we eat, transport them to different parts of the body & store or discard additional nutrients which are left.
To sum up, metabolism involves multiple bodily processes- our body has to recognize when it needs nutrients, create that feeling of hunger, food seeking behavior, food digestion, nutrient distribution, nutrition storage, halt of food seeking behavior, use of stored material & disposal of excess materials. In essence, metabolism is hardwired to our DNA. You may find two people have the same diet however one gains weight more than the other. This is usually the result of two factors: genetics & gene-environment interaction. Genes are you, environment is everything else: Gut health, food, eating habits, hormones, toxin exposure, inflammation level, microbiome, fitness & your stress levels.
After you reach the age of 40, multiple factors impact & slow down your metabolism. The control system for hormones become unstable, cortisol level goes up, testosterone goes down and so does muscle mass. Low muscle mass means low resting metabolic rate & slower calorie burn, meaning you are potentially at high risk of gaining weight. You lose fast twitch muscle fibre first. As you age you become less sensitive to insulin which spikes your blood sugar level. Besides, thyroid function may also be impacted with age. All these factors lead to slower metabolism.
If you feel that you are not losing weight inspite of following a diet & workout plan, genetics may be playing a role. It is important to note that through gene-environment interaction, genes are switched on & off based on your lifestyle cues. If you’re struggling with weight gain/weight loss resistance, you want to know about the genes that may be driving you to be more hungry or addicted to carbs, so that you can do something about how those genes are being expressed.
Let us discuss in detail about main genes that impact metabolism & weight
- Food intake~ FTO: This is also called fat mass & obesity associated. FTO acts as a nutrient sensor, affecting the amount of food a person wants to eat. Variations in the gene that encode for FTO can impact ability of FTO to regular food intake & hunger. People with certain variations in their genes have higher BMI. However, it does not mean that people having this gene would have slow metabolism( in early age) & become obese. Given that these folks have low carb low fat diet & indulge in regular workout & laborious work, they are less likely to be obese than those who don’t.
- Fat Metabolism~PPARG: Another gene that impacts metabolism & weight gain is the one that decodes for PPARG, a protein involved in fat metabolism. PPARG creates fat cells & helps with uptake of dietary fats from the blood. Too much activation of PPARG can lead to weight gain & increases risk of heart disease, diabetes & stroke. Obese individuals have high amount of this protein in fat tissue.
- Melanocortin-4 receptor or MC4R: This sits at the intersection of various metabolic processes. This helps control how much energy we consume & use and has an overall contribution to our feeling for hunger. Some people inherit a rare version of MC4R & these people are found to be slightly less overweight than those without it. People with genetic mutations in MC4R tend to gain weight from early childhood. MC4R deficient people have an increase in lean mass & increased linear growth in childhood.
- Fat breakdown~ADRB2: This plays an important role in breakdown of fat. Certain variations are linked with increased risk of metabolic syndrome in women. Prevalence of this syndrome is more in middle aged women than middle aged men. This is another gene that can help understand the relationship between genetics & weight gain.
- Stress~ FKBP5: This gene can make you more exposed to stress & age you quicker. This commands the body’s stress response system & contributes to slowing down of metabolism.
There are a couple of ways you could change the environment for your genes & metabolism: external exposure & its internal impact on our body. Your genes produce specific biomarkers that can be detected in your blood, urine, and hair that indicate the effect of exposure & susceptibility factors.
Our genomics based testing will help you find answers related to your metabolism.If you are looking for a personalized fitness solution & not sure whether you predisposed to slow metabolism, sign up for our genomics based fitness program here.
