Weight loss or weight gain is not only about the amount of calories you consume.
It’s also about how they affect your hormones.
And when certain foods over-stimulate your hormones (such as insulin), this can lead to accelerated weight gain, regardless of the calorie count.
So I no longer buy bread because of how it sky-rockets insulin.
Recent Research by Bao and Holt has measured a range of foods based on their insulin response, ranking them with a Food Insulin Index (Ref 1,2).
For educational purposes, here’s a summary of some of their notable findings below (I’ve highlighted some of the more commonly consumed foods to be especially wary of):
Food Food Insulin Index (higher is worse)
Jelly Beans 160
Mars Bar 122
Baked Beans 120
White bread 100
Whole meal bread 96
Ice tea 95
Ice cream 89
Raspberry jam 85
French Fries 74
Grain bread 71
Sustain (cereal) 71
special K (cereal) 66
Apple juice 64
Potato Chips 61
coca cola 60
Carrot juice 56
Full fat milk 33
All Bran cereal 32
Roast chicken 23
Peanut butter 15
So as you can see, the worst offenders included the Jelly Beans (160), Mars Bar, Yogurt and Baked Beans (120). All of these have high levels of refined added sugar.
The Potatoes have a surprising high Index of 121, and this is due to the high starch content which is essentially compact strings of glucose (sugar).
Still in the high zone, we can see Bread (100), cookies and ice cream. Bread contains a-lot of refined grains (flour), which are known to stimulate insulin, as well as high levels of carbohydrates (starch). Cookies and ice cream contain a-lot of added sugar.
Cornflakes were a surprise, right up there with croissants and donuts.
Coming down to lower levels we have some of the healthier staple foods such as beef (51), fish, cheese (45), pasta, chicken (23), vegetables, milk, eggs (31), and nuts.
And the winner is a food full of rich natural fats, the humble Avocado….long live the Avocado!
Why Do Some Foods have a Higher Insulin Index?
This depends on factors such as the amount of carbohydrates (“sugar”) as well as the glycemic index which refers to the speed that the food is converted into blood sugars. Protein also stimulates insulin.
It’s also known that when protein and carbs are mixed together in the same meal, they can generate a dis-proportionally higher jump in insulin.
This is why some health experts recommend that protein and carbs should be eaten at separate meals if high insulin is a problem.
What are the Effects of too much Insulin?
The effects of eating too many insulin stimulating foods can lead to insulin resistance, and eventually diabetes.
Diabetes is unfortunately on the rise and since 1995, it’s estimated to affect at least twice as many people by 2025 (3).
This is likely caused by the increasing availability and popularity of cheap junk food across the globe, as well as the trends towards more “screen time” and less outdoor activities.
What are the Signs of Insulin Resistance?
The signs of insulin resistance include:
- Having a large protruding belly (especially when the rest of your body is fairly slim looking)
- High Blood sugar levels (blood glucose tests from your doctor)
- Low HDL Cholesterol levels (the “Good” Cholesterol) (3)
- High Triglyceride (“Fat”) levels in the blood (3)
How can we reduce Insulin Resistance?
Ways to reduce insulin resistance include:
- Regular exercise (ideally 30 mins brisk walking as a minimum each day).
- Low carbohydrate or ketogenic diets
- Less alcohol (i think a small glass of wine is generally ok with a meal). However I think it’s good to have a few non-alcohol days each week too, especially if you are trying to lose weight.
- Less sugary soda drinks (eg coke / lemonade) and reduce sugary chocolate snacks and sweets. Go for the low or zero sugar versions. If you’re a chocolate lover, it’s possible to buy chocolate suitable for diabetics (in my opinion a healthier choice for everyone), or try dark chocolate (less sugar).
The Take Home
To stay slim and healthy we need to go easy on the foods that stimulate a-lot of insulin.
Try to limit foods like confectionery, breads, pastries, cakes, cookies, potatoes, fries, and ice cream.
Enjoy healthy foods such as vegetables, fish, chicken, beef, some fruit, eggs, nuts and seeds.
(1) Food insulin index: physiologic basis for predicting insulin demand evoked by composite meals
Bao, de Jong, Atkinson, Petocz, Brand-Miller. The American Journal of Clinical Nutrition, Volume 90 2009.
(2) An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods
Susanne HA Holt, Janette C Brand Miller, and Peter Petocz
(3) Evidence for an independent relationship between insulin resistance and fasting plasma HDL-cholesterol, triglyceride and insulin concentrations. A Laws G Reaven. Journal of Internal Medicine 1992.