By the way, I often read here and there, mostly in blogs, that “insulin suppresses hunger”. I frankly don’t know where this idea comes from. What actually happens is that insulin is co-secreted with a number of other hormones. One of those, like insulin also secreted by the beta-cells in the pancreas, is amylin – a powerful appetite suppressor. Amylin deficiency leads to hunger even after a large carbohydrate-rich meal, when insulin levels are elevated.
Abnormally high insulin levels – like those after a “healthy” breakfast of carbohydrate-rich cereals, pancakes etc. – lead to abnormal blood glucose dips soon after the meal. What I am talking about here is a fall in glucose levels that is considerable, and that also happens very fast – illustrated by the ratio between the lengths of the vertical and horizontal black lines on the figure below, from a previous post ().
Those hypoglycemic dips induce hunger, because the hormonal changes necessary to apply a break to the fall in glucose levels (which left unchecked would lead to death) leave us with a hormonal mix that ends up stimulating hunger, in an unnatural way. At the bottom of those dips, insulin levels are much lower than before. I am not talking about diabetics here. I am talking about normoglycemic folks, like the ones whose glucose levels are show on the figure above.
On a diet primarily of natural foods, or foods that are not heavily modified from their natural state, hunger patterns tend to be better synchronized with nutrient deficiencies. This is one of the main advantages of a natural foods diet. By nutrients, I do not mean only micronutrients such as vitamins and minerals, but also macronutrients such as amino and fatty acids.
On a natural diet, nutrient deficiencies should happen regularly. Our bodies are designed for sporadic nutrient intake, remaining most of the time in the fasted state. Human beings are unique in that they have very large brains in proportion to their overall body size, brains that run primarily on glucose – the average person’s brain consumes about 5 g/h of glucose. This latter characteristic makes it very difficult to extrapolate diet-based results based on other species to humans.
As hunger becomes better synchronized with nutrient deficiencies, it should promote optimal nutrient partitioning. This means that, among other things: (a) you should periodically feel hungry for different types of food, depending on your nutrient needs at that point in time; (b) if you do weight training, and fell hungry, some muscle gain should follow; and (c) if you let hunger drive food consumption, on a diet of predominantly natural foods, body fat levels should remain relatively low.
In this sense, hunger becomes your friend – and the best spice!
Ned, I agree that hunger can be your friend if you understand it. When I lost weight, I learned to enjoy hunger, because it meant I was in calorie deficit. However, most of us are raised to think that hunger is bad and needs to be treated.
ReplyDeleteNB insulin injected *into the brain* does reduce hunger, and this is where that *insulin reduces hunger* idea comes from.
I'm with Gretchen on the 'hunger is my friend because if I'm hungry then I'm burning fat' learned belief.
DeleteAlthough it wasn't till I started intermittent fasting that I was able to lock this thought process in...
I think the 'insulin reduces hunger thing' also comes from the correlation between those two things. And we all know how dangerous it is to mix up correlation and causation...
Keep up the good work,
George Super Boot Camps
High carbohydrat amounts and our cultural food sequence of breakfast, lunch and dinner seem to be mutually reinforcing mechanisms that could easily lead to overeating. Low carb and IF look like a natural remedy for this though.
ReplyDeleteIn regards of this, i wonder how much the rise in highly refined carbs over the last decades and the habit of snacking between meals are related to one another.
I wasn't aware that insulin dipped. If you look at the graphs in this study - insulin peaks differently, but falls back to the same point after different GI meals. However the increase in cortisol when the blood glucose is low is unnatural too and does not happen with a higher protein low GI meal
ReplyDeletehttp://pediatrics.aappublications.org/content/103/3/e26/F1.expansion.html
http://www.amazon.com/Instinctive-Nutrition-Severen-L-Schaeffer/dp/0890875022
ReplyDeleteYour last paragraph mirrors this book perfectly. In it the author explains the concept of "ANOPSOLOGY" which is to use your senses to adjust food intake (bite by bite) to your nutritional needs.
The case is made that this instinctive "6th" sense is completely overridden by modern industrial foods. I think the first part of your article explains that mechanism as well.
Interesting and relevant as usual, Thanks Ned.
This is similar to my theory on obesity. Satiety signals just are not triggered by consumption of carbohydrates. Fat, and more importantly protein, are very important for signalling satiety. Leptin sensitivity is increase via peptide YY, which also has an anorectic effect. Calorie per calorie, protein is the most satiating macronutrient by far.
ReplyDeleteIf we all focussed on eat meat more often our satiety signals would be in check, and our sensitivity to leptin would not diminish.
Who were the participants in this study? Were athletes or were they typical Americans? Did they have any protein with their meals?
I experience lasting fullness even up to a day after a carbohydrate refeed with loads of protein. I speculate that these people have poor glucose control to start with if they are carb loading three times a day.
I often hear from HCE users who use perception-based variable measurement (e.g., perceived hunger) in conjunction with other variables (e.g., waist circumference, weight, calorie intake) that they learned how to identify states where they are losing body fat without any loss of muscle.
ReplyDeleteThat is, there are certain feelings that are associated with burning body fat while still having enough liver glycogen that the use of amino acids from muscle tissue is not needed to feed the brain’s insatiable need for glucose.
Ned,
ReplyDeleteIf a person forced themselves to abide by a small caloric deficit -- say a total intake of 1800kcal/day on average -- and their metabolism adapted to that level, what would be the consequences?
I have read about this in relation to fat loss; i.e. a chronic caloric deficit causes a slow down in the metabolism, and weight loss stops. But if a person is already at their ideal weight, wouldn't a slight deficit -- relative to what is considered a "normal" intake amount -- result in increased longevity without any real negative effects? wouldn't any feelings of hunger eventually subside as the metabolism adjusted?
What I have noticed, and discussed with others on the Paleo type approach to diet, is that the hunger experienced on that diet has an entirely different "feel" to it than what is experienced with a higher carbohydrate diet. That is, the sense of wanting to eat is there, but it is not associated with a bad mood swing or desperate feelings. Intermittent fasting in such a state is not misery.
ReplyDeleteOn a higher carb diet the feeling is that you have to eat every four hours or so, and you can get quite grumpy and unpleasant about it.
With reduced or no carbs, you remain calm and probably go six hours, or more.
What this gets to, in my mind, is what the Paleo approach is all about: What not to eat, and a big part of that message is somewhat the second part ... "not to eat." That is, it as important not to eat as it is to eat the right things. The fasting state is a necessary part of metabolic regulation.
Where this goes wildly wrong, as I see it, for most people is the very first "meal" of the day, if that meal is loaded with carbs, as it probably is. From that moment forward the day is lost.
I don’t think there is a lot of support to the theory that calorie restriction leads to increased lifespan in humans. The link below discusses this in the context of an analysis based on the China Study II dataset.
ReplyDeletehttp://bit.ly/bFat8O
After reaching an ideal weight, calorie restriction is likely to lead to nutrient deficiencies, which may be why some people experience metabolic problems when they do that.
Nutrient deficiencies should lead to hormonal responses aimed at inducing nutrient intake. Such hormonal responses are not likely to lead to a sense of well-being, and may be pro-inflammatory.
One more link related to my comment above:
ReplyDeletehttp://bit.ly/yXgtOZ
Going hungry is a bad idea imo, especially straight up starving yourself(IF). Personally I gained nearly 100 pounds by intermittently starving myself and then gorging on junk food. I lost basically all that weight eating ad libitum whenever I wanted, for me all I had to do was change the quality of the food slightly and eat frequent meals to lose weight.
ReplyDeleteI think waiting for hunger can be good but for people with high stress hormones it can sometimes be hard to gauge when you actually need food. Stuff like IF will promote the release of these stress hormones. Sure you might lose weight fast but at the expense of what? your health? For some people it could backfire and drastically lower there metabolism so they won't even lose that much weight.
You give refined carbohydrates the blame but unsaturated fats(which the refined carbohydrates are always eaten with in a SAD)impair glucose stimulated insulin secretion. http://www.ncbi.nlm.nih.gov/pubmed/12031970
Cliff, you made a small error there. Here is the correct sentence:
ReplyDelete"Personally I gained nearly 100 pounds by gorging on junk food."
Its no big deal though, we all tend to confuse cause, correlation and effect.
@anonymous- you are right that it was mainly the junk food that caused my weight gain as I did intermittent fasting later on when I was skinny and didn't gain weight but it did run me into the ground.
ReplyDeleteI think the way I ate had a big deal to do with the weight gain though and not just the food I was eating. When I lost most of the weight I was eating mostly honey/peanut butter sandwiches, corn chips fried in corn oil, cheese, OJ and the occasional mcdonalds treat. The food I gained weight on wasn't that much different but instead of starving myself and eating giant meals I ate very frequently.
What do you think of eating ceylon cinnamon with http://nutritionfacts.org/?s=cinnamon with all carbohydrate meals rich meals?
ReplyDeleteFrom Harvard Health Letter ~3yrs ago:
"Cinnamon contains several chemicals that stimulate insulin receptors so glucose can get into cells and that means levels in the blood go down. " (http://paste2.org/p/1995093)
It makes sense that starving yourself and then eating huge meals could make you gain weight. In a world of scarce food the body will want to build up reserves while there is available food.
ReplyDeleteGreat article. I am also with Gretchen, I learn to like hunger when I am on a diet. Just as when I lift, I like the muscle burn. It means I'm making progress.
ReplyDeletehello is a good site I recommend
ReplyDelete