Insulin acts as the key which unlocks the cell to allow glucose to enter the cell and be used for energy

Insulin Resistance and Weight Gain

By wlr Contributor Dr Muhamad Usman MD

Hormones are powerful and you should not take them lightly. Several hormones may either speed-up or impede your weight loss success. Insulin is one such hormone.

Resistance to insulin causes diabetes and weight gain. Escaping insulin resistance can give you control over your blood sugar and your weight too!  

What is Insulin?

But, what is insulin? What does it do? Insulin is a hormone released by your pancreas - an organ in your abdomen. When you eat, your body senses that and signals your pancreas to release insulin.

Your body releases insulin in response to glucose, amino acids and fats in your meals (1-3). But, its secretion is highest when you eat sugary foods.

What Does Insulin Do?

After its release, insulin assists the entry of glucose from your food into your body cells. Think of insulin as a key that unlocks the door for glucose to enter into your body cells.

When your system gets loaded with glucose, it causes a shift in your metabolism. It slows down the breakdown of fat. More importantly, it starts the synthesis of new fat.

Insulin redirects excess glucose into fat cells and triggers ‘adipogenesis’- synthesis of fat (4-7). No wonder sugary stuff is so fattening!

Insulin Sensitivity vs. Insulin Resistance

Insulin sensitivity is the term for how your body responds to insulin. If your body is ‘sensitive’ to insulin, it means everything is on the right track. The key is turning the locks just fine and there is no need to worry.

But, things become different when ‘resistance’ replaces ‘sensitivity’. When you become resistant to insulin, it means the key is not turning the locks the way it is supposed to. Glucose is not entering into the cells and fat synthesis is on the rise (8).

Insulin Resistance - Cause or Consequence?

The link between insulin resistance and obesity has been a conundrum for health professionals - what comes first; insulin resistance or obesity?

The real pictured has just started to clear up a bit. It seems both go hand in hand.

Obesity causes insulin resistance and insulin resistance causes more weight gain.

Insulin Resistance and Obesity link

The Cause

The initiating event in the picture above seems to be an increase in body fat.

The fat you gain from extra calories and unhealthy lifestyle gets stored in your body. This fat, especially the fat around the abdomen, then instigates insulin resistance.

Researchers at the Stanford University School of Medicine made an interesting discovery.

They studied the effects of different body fats on insulin resistance. They found that abdominal fat caused an 80% increase in the risk of insulin resistance. In comparison, fat in other body parts increased the risk by 50-60% (9).

But, what makes abdominal fat a strong trigger for insulin resistance?

There are several explanations:

Abdominal fat cells release a substantial amount of adipokines. Adipokines are chemicals that counter the effect of insulin (10).

Moreover, increased fat brings about several inflammatory and metabolic changes.

These changes make the insulin ‘key’ dysfunctional (11).

The Consequence

The result of insulin resistance is an increase in body weight. This happens through different mechanisms.

First, insulin dysfunction starves your cells of much needed glucose. This can lead you to eat more and get crazy cravings for sugary food.

An increase in food cravings is also due to the effects of insulin on your brain. Researchers believe that insulin functions like leptin- it reduces appetite.

In insulin resistance, your brain too becomes resistant to the effects of insulin (12). This may result in an exaggerated appetite.

Insulin resistance also increases sex hormones, especially oestrogen. Increased oestrogen is an established risk factor for obesity (13-15).

Insulin Resistance, Obesity and Oestrogen link

Excess sugar overloads your systems. When that happens, insulin starts converting it into fat, as mentioned before.

How You Can Turn Tide - From Resistance to Sensitivity

Your lifestyle defines your health. Among factors that trigger insulin resistance, an unhealthy lifestyle is the most important.

Here are the top 3 lifestyle changes you need to make right away! These changes will bring your insulin sensitivity and body weight back to normal.

1. Make Systematic Changes in Your Diet Plan

Your diet can make your health or take it away from you. Carbohydrates, proteins and fats are important ingredients of your diet. Here’s how these ingredients should look in your diet:

  • Simple Carbs: According to experts at the University of Colorado, simple carbs worsen insulin resistance. Among these sugars, fructose is the most potent- it is the sugar found in sweetened beverages (16). Research has also shown that insulin sensitivity improves when you cut back on simple carbs (17).

    What you need instead is a diet rich in fiber. Fiber seems to cause a positive change in insulin sensitivity. You can get it from vegetables, fruits and whole grains.
  • Proteins: Proteins are famous for their satiety and weight loss promoting effects. But things are slightly different for proteins when it comes to insulin sensitivity.

    The good old ‘add protein to everything’ notion does not apply to insulin sensitivity. In fact, researchers believe that simply increasing the amount of protein can actually increase insulin resistance instead of decreasing it (18).

    What matters here is the quality of protein rather than quantity. According to research, certain protein types improve insulin sensitivity. These include proteins coming from soy products, fish, other forms of seafood and possibly poultry (18).
  • Fats: Saturated fats, without any doubt, worsen insulin resistance (19-20). What you need is unsaturated versions of fats. Research shows that adding unsaturated fats, like omega 3, into the diet results in improved body response to insulin (21).

2. Get Adequate Sleep

The importance of sleep cannot be stressed enough. Even a single night of sleep deprivation can reduce insulin sensitivity (22).

In further research, participants experienced as much as a 44% reduction in insulin sensitivity after only 12 days of shortened sleep (23). Now imagine what chronic sleep deprivation could do to your insulin sensitivity?

The solution is quite simple. All you need is 7-8 hours of quality sleep daily. (See my article on sleep and weight loss for more on this subject.)

3. Exercise is Important

Exercise makes your insulin work better. It makes insulin open up the gates, just the way it would normally do!

Research shows that regular exercise can improve insulin sensitivity 4-fold (24).

According to researchers, you should do 150 minutes of moderate intensity workouts on weekly basis. Five sessions, each lasting 30 minutes, would be ideal - but you can still achieve beneficial effects by doing more sessions of, say, 10-20 minutes duration.

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  1. The effect of rate and dose of glucose infusion on the acute insulin response in man.
  2. Human protein metabolism: its measurement and regulation.
  3. Fatty acids and insulin secretion
  4. Regulation of the Conversion of Glucose into Fat in White Adipose Tissue by Insulin
  5. Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man.
  6. De novo lipogenesis during controlled overfeeding with sucrose or glucose in lean and obese women.
  7. NIH study shows how insulin stimulates fat cells to take in glucose
  8. Insulin resistance, insulin insensitivity, and insulin unresponsiveness: a necessary distinction.
  9. Preferential fat deposition in subcutaneous versus visceral depots is associated with insulin sensitivity.
  10. Adipokines and Insulin Resistance
  11. What causes the insulin resistance underlying obesity?
  12. Brain insulin and feeding: a bi-directional communication.
  13. Insulin resistance in PCOS.
  14. The Estrogen Hypothesis of Obesity
  15. Serum TSH, T4, and Thyroid Antibodies
  16. The role of carbohydrates in insulin resistance.
  17. A lower-carbohydrate, higher-fat diet reduces abdominal and intermuscular fat and increases insulin sensitivity in adults at risk of type 2 diabetes.
  18. Role of dietary proteins and amino acids in the pathogenesis of insulin resistance.
  19. Saturated fatty acids and insulin resistance.
  20. Type of dietary fat and insulin resistance.
  21. High omega-3 fat intake improves insulin sensitivity and reduces CRP and IL6, but does not affect other endocrine axes in healthy older adults.
  22. A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects.
  23. Sleep restriction for 1 week reduces insulin sensitivity in healthy men.
  24. Invited review: Effects of acute exercise and exercise training on insulin resistance.
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