Fact or Fiction: Adding Fat To Your Meal Will Lower Insulin Response

When browsing the health and fitness boards or blogs, the sheer number of claims made without any scientific evidence-base is overwhelming. This 'broscience' as it is affectionately referred to by those of us 'in the know', is akin to the Siren's of Homer's Odyssey; guiding innocent and uninitiated souls to an unwitting doom at the hands of misinformation.

Broscience Fact: Adding Fat To A Meal Will Lower The Insulin Response

It is common 'knowledge' that adding some fat to a meal will help to reduce the insulin spike it will provide. If I had to guess, I would suspect that this fallacy first came about as some eager trainee mis-read the results of the studies suggesting that fatty meals are less insulinogenic than low fat meals.

Evidence-Based Reality

Unfortunately, the picture pained by the scientific evidence is somewhat different to the commonly accepted paradigm. For example, Collier & O'Dea (1983) examined the effect of co-ingesting 50g of butter on glucose, insulin and gastric inhibitory polypeptide responses to 50g of carbohydrates (potato) or 50g protein (low fat veal) in their participants. The addition of fat to a carbohydrate meal did result in lower blood glucose levels. However, the insulin response was not reduced.

The Take-Away

So, next time you feel inclined to add a handful of nuts to your rice to 'nullify' the insulin response from your bolus carbohydrate dose, remember that you are doing so under false pretenses.

While the addition of fat to a meal may increase satiety, it may do little in the way of keeping you lean!

Reference:

Collier G, & O'Dea K. (1983). The effect of coingestion of fat on the glucose, insulin, and gastric inhibitory polypeptide responses to carbohydrate and protein. Am J Clin Nutr, 37(6):941-4.