Your genetics determine whether you're more prone to weight gain, lactose intolerance, or for that matter how well your body processes caffeine. As per a 2020 report in Nutrients, genetic differences in how we process food started in Africa and changed over time as humans migrated across the world over the past 100,000 years. As people adapted to new climates and diets, their genes evolved in ways specific to their region. For example, Northern Europeans are more likely to digest lactose as adults compared to East Asians or Africans.

 

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Modern research, including genome-wide studies, has identified many genes linked to how our bodies absorb nutrients, break down fats, and store energy. These genetic variations can influence how different people respond to certain foods, allergies, and intolerances leading to unique interactions between diet and health. Understanding these factors allows you to eat smarter, preferring foods that fuel your body properly, and prevent discomfort.

 

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How do genes influence nutrient absorption, food sensitivities, and metabolism?

There is a strong relation between your genetic makeup and the type of diet that suits your body. Now, this means that how your body processes food, influencing nutrient absorption, food sensitivities, and metabolism. Recent research has pinpointed specific genes that affect these processes. 

Nutrient Absorption: Genetic variations can impact how efficiently your body absorbs certain nutrients. For instance, mutations in the MTHFR gene can affect folate metabolism, potentially leading to deficiencies. A 2023 study in GeneFood states that about 75 per cent of people lose the ability to digest lactose as they grow older, meaning they can no longer break down dairy products properly. Those who can still digest lactose into adulthood have what’s called “lactase persistence”, a genetic trait that allows them to continue producing the enzyme needed to digest milk.

Another important genetic variation affecting nutrient absorption involves the HFE gene, which plays a role in iron regulation. Certain variations in this gene can lead to hereditary hemochromatosis (HH), a condition where the body absorbs too much iron. If left untreated, excess iron can build up in the organs and become life-threatening. 

 

Food Sensitivities: Your genetic makeup can also determine your tolerance to specific foods. A 2025 study in the journal Gastroenterelogy shows that variations in the sucrase-isomaltase (SI) gene may influence how your body processes sugars, affecting your preference and consumption of sweets.

 

Metabolism: The way our bodies process nutrients and medications is influenced by complex interactions at different stages—absorption, distribution, metabolism, and excretion. These interactions can impact how well a treatment works or lead to unexpected side effects. A 2020 review study in Clinical Nutrition shows that in the liver alone, 47 out of 57 human enzymes play a key role in processing hormones and vitamins. Since metabolism is regulated by multiple genetic means, understanding a single metabolic step requires analysing several individual reactions. 

 

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Eating According to Your Allergies and Intolerances

Not all food reactions are the same. Some can be life-threatening, while others may simply cause discomfort. Understanding the difference between food allergies, intolerances, and sensitivities is key to making smart dietary choices.

1. Food allergies trigger an immune system response, which can lead to serious reactions like swelling, difficulty breathing, or anaphylaxis. Even a tiny amount of the allergen can be dangerous. Common culprits include nuts, shellfish, dairy, and soya. 

What to do:

• Use pumpkin seeds, sunflower butter, or tahini instead of almonds or peanut butter for healthy fats.

 

2. Food intolerances occur when your body lacks the necessary enzymes to properly digest certain foods, leading to digestive issues like bloating, gas, or diarrhea. Lactose intolerance (difficulty digesting dairy) and gluten intolerance (found in wheat products) are common examples. 

What to do:

• Swap regular dairy for almond, oat, or coconut milk for a creamy texture without digestive issues. Opt for lentils, chickpeas, or hemp seeds instead of tofu for plant-based protein, if you have soya sensitivity.

 

3. Aparently less severe than allergies but can still cause discomfort, food sensitivities including headaches, joint pain, or fatigue. Sensitivities to foods like MSG, artificial sweeteners, or histamine-rich foods are often reported.
 
What to do:

• For gluten sensitivity, choose quinoa, buckwheat, or brown rice instead of wheat-based products. 

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Diet Tips To Improve Digestion

• Stick to fermented foods like kimchi or sauerkraut to boost gut bacteria.
• Choose soaked chia seeds or flaxseeds to improve fibre intake and digestion.
• Drink ginger or peppermint tea to ease bloating.

 

Diet Tips For Steady Energy Levels

• Replace sugary snacks with protein-rich nuts or hummus with veggies to prevent energy crashes.
• Eat whole grains like oats or instead of refined carbs for energy.
• Hydrate with coconut water or herbal teas to support electrolyte balance.

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Additional Tips

1. Read labels before puchasing packed food items. Watch for hidden allergens like casein (milk), wheat starch (gluten), or soy lecithin in processed foods.
2. Prep meals in advance to stay in control. Try batch-cooking allergen-free meals or keeping snacks like hummus with veggies or fruit with seed butter on hand.

Eating right is about what works best for your body. By understanding your genes, allergies, and metabolism, you can make smarter food choices that fuel your energy, improve digestion, and support long-term health. Whether it’s swapping out trigger foods, tailoring meals to your metabolic type, or choosing nutrient-rich alternatives, a personalised approach to nutrition helps you feel your best every day.

 

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