Your body is not your enemy, and neither is your genotype
Millions of people follow diets, count calories, exhaust themselves at the gym… and lose almost nothing. The answer is not in your willpower. It's in your genes.
FTO: the hunger gene that never switches off
The rs9939609 variant of the FTO gene (Fat Mass and Obesity Associated) is the most strongly obesity-associated genetic variant ever identified. Carriers of the AA variant have on average 1.67 times greater risk of obesity. They are less sensitive to leptin, the satiety hormone, and show higher post-meal ghrelin levels.
Good news: 150 minutes of moderate physical activity per week cuts this variant's effect in half. This is scientifically proven.
MTHFR: when your body doesn't process folate efficiently
The MTHFR gene produces a key enzyme in the methylation cycle. The C677T and A1298C variants, very common (40–60% of the population carries at least one), reduce this enzyme's activity. The result: less efficient carbohydrate and fat metabolism, and greater difficulty burning body fat.
VDR and vitamin D: the overlooked link to weight
Vitamin D is not just a bone nutrient. VDR receptors are present in fat cells, and several variants of the VDR gene (BsmI, TaqI, FokI) alter their sensitivity. Vitamin D deficiency is associated with insulin resistance and visceral weight gain, independently of caloric intake.
APOA2 and saturated fat: it all depends on your genotype
The APOA2 gene regulates the production of an apolipoprotein that affects lipid metabolism. CC variant carriers who consume more than 22g/day of saturated fat have a significantly higher BMI. Non-carriers show no difference at all. Same diet, two completely opposite outcomes depending on genotype.
What this means in practice
Nutrigenomics does not replace a healthcare professional. But it gives you something essential: understanding why your body responds differently. It's not a question of discipline, it's a question of personalised biology.
If you already have a raw DNA file (23andMe, AncestryDNA, MyHeritage…), FuelYourDNA analyses your variants in under 60 seconds, from €19.
Sources: Frayling et al. (2007) Science; Corella et al. (2009) J Nutr; Wehr et al. (2010) Eur J Endocrinol.