4 min readNew DelhiJul 17, 2026 06:00 AM IST
Blood sugar is often thought to be closely tied to body weight and eating habits. Many people assume that those who are lean, physically active and eat a balanced diet are unlikely to experience significant blood sugar spikes, while people with less healthy lifestyles are expected to have poorer glucose control. However, real-life experiences and emerging research suggest that the picture is far more complex.
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.
Some healthy, lean individuals experience unexpectedly high blood sugar spikes after meals, while others on diets that appear less nutritious maintain relatively stable glucose levels. This raises important questions about the many factors that influence blood sugar beyond food choices alone. Could genetics, muscle mass, sleep, stress, hormones, the gut microbiome or differences in insulin sensitivity help explain these contrasting responses? We asked an expert to unpack why blood sugar regulation varies so widely from person to person and what it means for everyday health.
Blood sugar spikes in healthy, lean people
Kanikka Malhotra, consultant dietician and certified diabetes educator, tells indianexpress.com, “Body weight is a poor proxy for metabolic health. A person can be thin outside and metabolically obese inside, a condition often called TOFI, thin outside, fat inside, where visceral fat sits quietly around the liver and pancreas even when BMI looks perfect. Add to this genetic variation in insulin secretion, receptor sensitivity and beta cell reserve, and you get two people eating identical thalis with very different glucose curves.”
She adds that some lean individuals inherit a smaller first-phase insulin response, meaning their bodies release insulin slightly later after a meal, allowing glucose to climb before control kicks in. “Meanwhile, someone heavier but physically active and muscular may be shuttling glucose efficiently into muscle glycogen stores, blunting the spike entirely. Muscle, not weight, is often the real metabolic currency. This is why glucose stability should never be assumed from appearance alone, and why every lean person is not automatically a metabolically healthy person,” notes the expert.
Lifestyle factors that influence blood sugar
Post-meal glucose is not decided at the plate; it is decided by the state of the body receiving that plate. One poor night of sleep can reduce insulin sensitivity by nearly a third the next day, Malhotra says, making an identical breakfast spike higher simply because you slept badly. Cortisol from unmanaged stress pushes the liver to release stored glucose even without eating anything, so a stressful morning meeting can spike sugar as much as a sugary snack.
“Muscle mass matters enormously since muscle is the largest glucose storage site in the body, meaning two people with the same weight but different muscle mass can have very different curves. Gut microbiome diversity influences how quickly carbohydrates are broken down and absorbed. Even meal sequence matters; eating vegetables and protein before rice or roti can meaningfully flatten the curve. Glucose control is really a 24-hour lifestyle report card, not a single meal decision,” mentions Malhotra.
Story continues below this ad
When blood sugar spikes need attention
Quick Quiz
See if you can answer this:
According to experts, when should blood sugar spikes become a cause for concern?
A. Every time your blood sugar rises after a meal.
B. Only after eating sugary foods or desserts.
C. When high spikes occur repeatedly, recovery is slow, or fasting glucose gradually increases over time.
Story continues below this ad
D. Whenever a Continuous Glucose Monitor shows any change in glucose levels.
▼ Reveal the answer
✅ Correct answer: C
An occasional rise in blood sugar after eating is a normal part of physiology. What matters is whether glucose levels repeatedly spike, take a long time to return to baseline or are accompanied by rising fasting glucose over time. If this pattern persists, doctors may recommend tests such as HbA1c, fasting insulin or an oral glucose tolerance test. Regular exercise, prioritising protein and fibre, getting enough sleep and strength training can all help improve glucose regulation.
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.