T Nation

Insulin & Eating ?


Regulary eating meals that result in a huge insulin response will predispose you to gaining fat in the presence of a calorie surplus.

Is this correct?


It isn't that simple. You can't ignore genetics and individual metabolism. Some people can eat whatever they want and remain leaner than others. Define "huge" as far as insulin. Insulin is one of the most anabolic hormones in your body. Trying to avoid any increase of it may be helpful in DIETING, but may hold back progress when it comes to gaining muscle mass.


Oh good, Professor X. I'm eager to get your input.

Ok... well I meant "huge" as it might relate to the individual. Let rephrase the whole question.

Ignoring fiber, vitamins, and minerals, if the "average" person was to bulk or maintain on a diet with meals that consisted of:
- ideal amounts of fat
- ideal amounts of protein
- carbohydrates that provide for stable, moderated insulin levels (as opposed to crazy spikes at each meal)

would they gain less fat than on a diet that consisted of:
- ideal amounts of fat
- ideal amounts of protein
- no low insulin index carbs, only straight glucose

Keep in mind, I'm talking about IN GENERAL. I do understand that everyone is different. I'm just talking about ON AVERAGE.


It is POSSIBLE, but again, the largest factor is overall food intake and what your body is geneticallly inclined to do with them based on every other factor like activity level and intensity in the gym. You are trying to prove that a "calorie isn't just a calorie" and I am personally not convinced that changing from low to high carbohydrates will make that much of a significant difference in someone already eating more calories than they need to maintain their body weight. It would be IDEAL to avoid large spikes and lulls in insulin.

However, assuming someone had everything else on point from meal timing to every other nutrient available, I think GENETICS would be the largest contributing factor.

In short, while it is possible someone could gain more fat from that alone, I personally don't believe the effect would be as drastic as some would have you believe on a HYPERcaloric diet. It becomes much more of an issue when taking in less calories than your body needs.


So I take it that it's still a controversial topic. Perhaps I've been reading too much Berardi because in Massive Eating, he talks about getting a glucose tolerance test to see if one should use a reduced carbohydrate diet to bulk up.


I think anyone who spends too much time reading any one author is making a mistake. You end up becoming some guru's disciple instead of someone who thinks for themselves and builds THIER OWN background of knowledge. Past that, experience as far as what works for you is still the best method. That means try it and keep it if it works. If not, try again. Why would someone go that route instead of simply eating well to gain muscular body weight? Some of you spend more time trying to microanalyze what is involved instead of ever actually DOING anything. It might do you well to consider that looking for the "one best way" is one truly ridiculous way to get started in this.


Like prof X said, its extremely anabolic. Like you said, it'll make you gain fat faster.

I think as long as you dont mind gianing some fat, keep the insulin high. I put on a serious, IMO, amount of muscle this winter while drinking a gallon of whole milk spread throughout the day. Now, one could attribute this to extra cals, which obviously played a huge part, but keeping my body in an anabolic state all day, then sucking down a MD shake prebed (to keep myself anti-catabolic) definitly had something to do with it.

That said, yes, I did put on quite a bit of fat, too. But I'd also attribute some of that to me gaining the 'freshman 15' and the low-quality food at my cafeteria.


According to researcher Lyle McDonald, you WONT store more fat. Here's what he had to say about it:

"Bottom line: it takes absolutely miniscule amounts of insulin to pretty much affect fat metabolism. So, says ironaddict, just eat fat; so say sBerardi, food combining is the voodo nutrition key to all of this. Sorry, doesn't work, dietary fat affects fat cell metabolism with NO increase in insulin.

Partitioning is about 75-80% determined by factors outside of your control. training is probably the single most important thing you can do to affect where the calories go. not creating too large of a surplus helps too. bascially, you can only build so much muscle per unit time, calories beyond what's needed go to fat and that's pretty much going to be irrespective of what you eat IMO.

for a fixed number of calories over maintenance, I consider it unlikely that you will see an iota of difference in terms of quality of weight gain for substitutions of one carb over another. I could be wrong, wouldn't be the first time. the confound, of course, is that nobody eats the same number of calories with low vs GI foods.



I agree with him...that it doesn't matter very much because there are other stronger factors involved with how someone gains weight, the most important of which being TRAINING, OVERALL CALORIC INTAKE and GENETICS. To claim high GI foods simply all lead to fat gain is to ignore those factors.

Most people don't train very hard. I was in Gold's yesterday and the amount of half assed training I saw while walking the treadmill was insane. That is why most of the people there look like overweight couch potatoes and why more of the people at the more hardcore gym I usually go to look like they actually workout. Specific carb intake has little to do with it.


Oh well btw, I don't think I mentioned that it was Lyle McDonald that claimed you could replace all of your low glycemic cards with straight glucose and that it would make no difference in body composition changes, while bulking (or maintaining). This is disregarding vitamins/minerals/fiber.

He also posted this:
Obes Rev. 2006 May;7(2):219-26. Links
Glycaemic index effects on fuel partitioning in humans.

  • Diaz EO,
  • Galgani JE,
  • Aguirre CA.

Laboratory of Energy Metabolism and Stable Isotopes, Institute of Nutrition and Food Technology (INTA), University of Chile, Ave. El Libano 5524, Macul, Santiago, Chile. ediaz@inta.cl

The purpose of this review was to examine the role of glycaemic index in fuel partitioning and body composition with emphasis on fat oxidation/storage in humans. This relationship is based on the hypothesis postulating that a higher serum glucose and insulin response induced by high-glycaemic carbohydrates promotes lower fat oxidation and higher fat storage in comparison with low-glycaemic carbohydrates. Thus, high-glycaemic index meals could contribute to the maintenance of excess weight in obese individuals and/or predispose obesity-prone subjects to weight gain. Several studies comparing the effects of meals with contrasting glycaemic carbohydrates for hours, days or weeks have failed to demonstrate any differential effect on fuel partitioning when either substrate oxidation or body composition measurements were performed. Apparently, the glycaemic index-induced serum insulin differences are not sufficient in magnitude and/or duration to modify fuel oxidation.

This seems to demonstrate the overall shittiness of the glycemic index's ability to calculate the end behavior of insulin considering that when you introduce fiber/other carbs/anything etc. into the mix, it changes.

Why is the notion of insulin being the "end all" factor in fat/muscle gain so widespread if there's really no apparent scientific evidence to support it. This sentiment is seen in the articles by Berardi, Poliquin, Serrano, and many others. Based on what I've been reading (especially on this site), I thought that it was a commonly held belief that excess insulin promoted fat storage.
What gives?


People are uneducated and (gym-wise) inexperienced. That is what gives. Many don't have any formal foundation in biology and wouldn't understand a study's abstract in the first place which is why they rely on "gurus" to tell them what is right or wrong as they ignore the possibility the guru may be wrong or misguided.

I hadn't done much research on this topic specifically (and thank you for the study posted), however, I have been to school for this for several years and I have been training about that long as well. There are simply more things you pick up over years of formal study than someone would get if they tried to "teach themselves" everything.

Controlling that insulin release becomes a much larger factor when dieting. When gaining, using that insulin to aid in gaining more muscle mass is the way I have always approached it.

Also, you wrote "excess insulin" and that doesn't make much sense.

I would always recommend a biology and A&P textbook over reading what many of the authors you listed have to say. I would also take the words of someone very developed over the words of someone who isn't more seriously when it relates to bodybuilding. Nothing takes the place of experience.

You also have to take into account that much of this info is opinion more than fact. It is and will always be up to you to inform yourself beyond that.


I think I meant to say excessive. In that, I really meant, something to the effect of eating a ton of glucose as compared to eating a ton of vegetables (of equal caloric value).

You said in your post "When gaining, using that insulin to aid in gaining more muscle mass is the way I have always approached it." This implies that believe that manipulating insulin DOES have an effect.

Lyle McDonald whose stuff I have been reading lately believes this to not be true and some of the studies he posts reflect this. I'm wondering on what you base this notion?


The same notion that implies that taking in more carbs after training along with protein may help absorption of that protein leading to more growth. Looking at a study of sedentary obese middle aged women wouldn't be the place to see if this is effective.

That means focusing in on protein when eating but eating enough carbs to aid in digestion even in some meals that do not follow training alone. That is assuming the goal is to gain weight.