Why One Diet Doesn’t Fit All: The Case for Personalized Nutrition- by Simran Wadhwa

I am Simran Wadhwa a nutritionist at The Kenko Life.

In a world filled with diet trends — keto, vegan, intermittent fasting, paleo — it’s tempting to believe there’s one “perfect” diet out there. You might see your friend thrive on a low-carb plan, while you feel sluggish on the same. Why does this happen?

Because when it comes to nutrition, one size doesn't fit all. Here's why:

1. Our Bodies Are Biologically Unique: Each person has a unique genetic makeup. These genes influence how we metabolize food, absorb nutrients, manage blood sugar, and even feel hunger or fullness.

Example:

Some people are genetically predisposed to process fats efficiently, while others may do better with more carbohydrates.

A genetic variant may make caffeine energizing for one person and anxiety-inducing for another.

Nutrigenomics, the study of how food interacts with genes, is helping to explain why personalized diets work better than general plans.

2. Cultural and Lifestyle Factors Matter: Our diets are deeply influenced by culture, environment, and lifestyle.

3.  A traditional South Indian diet might include fermented foods and rice - rich in probiotics and complex carbs.

4. A Mediterranean diet relies heavily on olive oil, fish, and fresh produce.

5. Someone with a physically active lifestyle will have higher calorie and protein needs than a sedentary office worker.

Personalized eating plans must respect cultural food preferences and daily routines to be sustainable.

3. Emotional and Psychological Needs Differ: Food isn’t just fuel - it’s also emotional and social. Some people eat when they’re stressed, while others lose their appetite. This impacts dietary needs and patterns.

4. A restrictive diet might trigger binge eating in one person.

5. Someone with a history of disordered eating may need a gentler, more intuitive approach.

   
   

Mental and emotional wellness must be considered when crafting an effective diet plan.

4. Health Conditions Require Customization: Chronic conditions can make or break a diet’s effectiveness. A diet that works for someone with PCOS may worsen symptoms in someone with hypothyroidism. Here’s how:

5. Diabetics need to manage carbohydrates carefully.

6. People with kidney disease must monitor protein, potassium, and phosphorus.

7. IBS sufferers may benefit from a low-FODMAP diet, while others wouldn’t.

Medical history plays a huge role in determining what’s “healthy” for an individual.

5. Gut Microbiome: The Hidden Key: Emerging science shows the gut microbiome — the trillions of bacteria living in our digestive tract — plays a huge role in how we respond to food. 

Two people can eat the same meal but have vastly different blood sugar and fat responses.

A diverse gut microbiome supports better digestion, immunity, and even mood.

Because everyone’s gut bacteria are unique, our response to the same diet can vary dramatically.

There is no single “best” diet that works for everyone. Factors like genetics, lifestyle, health status, cultural background, and even gut bacteria all influence what your body truly needs.

So instead of chasing trends, ask:

• What foods make you feel your best?

• What’s realistic and enjoyable for your lifestyle?

• Are you supporting your long-term health, not just short-term goals?

The best diet is one that’s tailored to you — flexible, balanced, and sustainable.