Post by Emily White
Insulin is a hormone made by the pancreas that has important effects on the metabolism of carbohydrates, fats and protein by promoting the absorption of particularly, glucose from the blood into fat, liver and skeletal muscle cells. Insulin is coined the ‘fat storage hormone’ and therefore tends to get a bad rap, however there is no denying the importance of insulin in order to shuttle vital nutrients into cells (like protein and glycogen into muscles). Insulin secretion isn’t the problem- chronically elevated and insulin resistance is. This brings us to dairy and the effect it has on insulin response.
Most dairy products (with the exception of butter and cheese) elicit a rather large insulin response. This is not solely to do with the lactose content but more so the combination of protein (casein and whey) and the carbohydrates that is the cause of this significant insulin release. Milk (whether it be skim or whole) is considered to be associated with the greatest insulin release with two studies suggesting that milk could in fact illicit a greater insulin response than white bread (1, 2).
So the question remains: if you are trying to lose weight is dairy problematic? Dairy products are nutrient dense and are very growth promoting so if you are into body building or wanting to pack on a bit of size, this is great. However if you want to lose fat then chugging back on five flat whites per day may not be doing you any favors. In saying that many of the studies done on the effects of insulin response and dairy products (3, 4) have used low-fat dairy as opposed to full-fat, thereby in my opinion affects the results. This is due to many studies showing that people who consumed full fat dairy over low-fat were slimmer (5), had the lowest risk of diabetes (3) and had lower risks of heart disease and stroke (6)- all of which are related to insulin resistance.
At the end of the day, everyone is different and what works for one person may certainly not work for others. I am not saying that if you are trying to lose fat you need to go to the fridge and throw out your organic non homogenised Lewis road (because that would be a crime) but be mindful of the effects that consuming large amounts of dairy can have on your insulin response and therefore your ability to lose fat. As said earlier, dairy appears to have positive effects on strength and mass gain so if you’re a gym goer looking to put on a bit of size incorporating it into your diet can be a good thing.
In the end, personal results are what matters most. If you consume dairy, make sure it’s full fat (the reasons are outlined in this post), and maybe consider that if you are trying to lose fat, it could be a good idea to ditch the excessive milky coffees! Replace it with coconut milk, unsweetened almond milk or a dash of cream- easy!
1. Nilsson M, Stenberg M, Frid AH, Holst JJ, Björck IM. Glycemia and insulinemia in healthy subjects after lactose-equivalent meals of milk and other food proteins: the role of plasma amino acids and incretins. The American Journal of Clinical Nutrition. 2004;80(5):1246-53.
2. Östman EM, Liljeberg Elmståhl HG, Björck IM. Inconsistency between glycemic and insulinemic responses to regular and fermented milk products. The American Journal of Clinical Nutrition. 2001;74(1):96-100.
3. van Meijl LE, Mensink RP. Low-fat dairy consumption reduces systolic blood pressure, but does not improve other metabolic risk parameters in overweight and obese subjects. Nutr Metab Cardiovasc Dis. 2011;21(5):355-61.
4. Hoppe C, Molgaard C, Vaag A, Barkholt V, Michaelsen KF. High intakes of milk, but not meat, increase s-insulin and insulin resistance in 8-year-old boys. Eur J Clin Nutr. 2004;59(3):393-8.
5. Holmberg S, Thelin A. High dairy fat intake related to less central obesity: A male cohort study with 12 years’ follow-up. Scandinavian Journal of Primary Health Care. 2013;31(2):89-94.
6. Kratz M, Baars T, Guyenet S. The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease. Eur J Nutr. 2013;52(1):1-24.