Yes, a low-carb diet greatly lowers your insulin
, medical review by Dr. Bret Scher, MD
in Insulin 
Is “eat less and move more” really the only thing you need to know in order to lose weight?
Why is it then that most people lose weight on an LCHF diet, even when eating until satisfied and without even any increase in exercise?
The best explanation, in a simplified version, looks like this:
Carbohydrates – > insulin – > obesity
Thus more carbohydrates lead to more insulin which leads to more fat accumulation. With more details this can be written as follows:
Too many (bad) carbohydrates – > pathologically high insulin levels – > obesity
What constitutes “too many” varies from person to person depending on sensitivity and activity level (how much carbs you burn). Intensely exercising young men can often tolerate a fair amount of carbs, while heavily overweight older individuals with diabetes can only tolerate minimal amounts without problems.
The opposite is the following:
Less carbs – > lower insulin levels – > loss of excess fat
Insulin is a fat storing hormone. And the easiest way to increase your insulin levels is to eat more carbohydrates. The easiest way to lower insulin levels is to eat fewer carbohydrates.
This seems very straight forward. But some are still adamant opponents. Without being able to come up with any better explanation as to why a low-carbohydrate diet works (it does) they still don’t want to accept this explanation. They come up with all kinds of objections. Some don’t even want to recognize the most basic, that carbohydrates increase insulin levels or that a low-carb diet lowers insulin levels.
Their complicated objections don’t matter much in reality. The truth is clear in study after study on humans. Insulin levels are much higher when you eat a lot of carbohydrates and lower on a low-carb diet. The figure above (from Boden et al.) is one example.
Here are some more:
Much lower insulin levels on a low-carbohydrate diet
Figure from Noakes et al.
Figure from Hernandez et al.
Longer trials
The insulin-lowering effect of low-carb diets has also been demonstrated for fasting insulin levels, in longer RCTs like these: NEJM 2003, Lipids 2009.
Lower insulin, lower insulin, much lower insulin
Does a low-carbohydrate diet lower insulin? There is only one answer: Yes, insulin levels decrease greatly throughout the entire day.
One could only wish that the insulin deniers could at least accept something this basic.
Previously
The #1 cause of obesity: insulin
P.S.
Even fasting insulin levels have been shown to be lower on a low-carb diet (for example: Samaha et al., Volek et al.)