Too Much Protein, Fat, May Lead to Insulin Resistance

A clue about the blood chemistry of obese people who develop insulin resistance, a precursor to diabetes, has been confirmed in animal studies at the Duke University Medical Center.

Obese people have been found to harbor proteins called branched-chain amino acids (BCAAs) at far higher levels than non-obese people. The suspicion has been that these amino acids, in combination with a high-fat diet, contribute to insulin resistance. The team found that the BCAA signature in obese humans consisted of the branched-chain amino acids themselves, plus a cluster of several products related to the bodys breakdown processes for BCAA.

In the case of the amino acids, we also are finding increased levels of their metabolic breakdown products, which suggests the whole system for handling the amino acid metabolic process has been overloaded, said senior author Christopher Newgard, Ph.D., director of the Sarah W. Stedman Nutrition and Metabolism Center and W. David and Sarah W. Stedman Distinguished Professor at Duke. Our rat studies show that this overload causes changes at the cellular level that can lead to insulin resistance.

To determine whether the BCAA signature in obese humans might signal that their intake is harmful, the scientists performed a feeding study in rats that showed an independent contribution of BCAAs to insulin resistance.

These findings, however, would need to be confirmed in studies with people before any dietary recommendations could be issued, said Laura Svetkey, M.D., director of the Duke Hypertension Center, director of clinical research at the Sarah W. Stedman Nutrition and Metabolism Center, and co-senior author of the study, published in Cell Metabolism.

"Insulin resistance occurred in animals with a diet high in the branched-chain amino acids, but only if they were ingested along with a high level of fat in the diet, Newgard said. Because obese humans tend to ingest high-fat diets, the combination of high-BCAA and high-fat intake might contribute to insulin resistance in obese humans, but additional studies are needed. BCAAs constitute as much as 25 percent of amino acids in dietary protein, and are particularly enriched in diets high in animal (meat) proteins.

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[Thineeyebesingle]

Which amino acids was it?!

[DukeMedicine]

@Thineeyebesingle The abstract for the study has more details:

Metabolomic profiling of obese versus lean humans reveals a branched-chain amino acid (BCAA)-related metabolite signature that is suggestive of increased catabolism of BCAA and correlated with insulin resistance. To test its impact on metabolic homeostasis, we fed rats on high-fat (HF), HF with supplemented BCAA (HF/BCAA), or standard chow (SC) diets. You can find the rest of the abstract on Pubmed.

[MikeEnRegalia]

I wonder why the Inuit - when on their original diet of almost 100% fatty meat - don't develop insulin resistence, diabetes or obesity. And it doesn't seem to be in their genes either, since they get these conditions when they adopt a western grain based diet.

BTW: Most low-carb diets today advocate an *adequate* intake of protein. It's a common misunderstanding of low-carb to mean that you base your diet on protein.

[KarinOll]

My question is, and that was not made clear in that clip: WHAT KIND OF FATS? What fat did they feed the rats? Some hydrogenated oils? Does their research/investigation speak of all groups of fat? I mean what about the healthy cold pressed oils, or the coconut oil for heated things? Should they also cause that? I doubt that.

[richmanpoman1]

@tickyul I tend to agree. I think that it is irresponsible of the medical industry not to tell people to eat low carb, but not to overdo the heavy proteins and fats. It would help if monsanto and big agra wouldn't be messing with our food though, that is a huge drawback, as buying organic can get costly, but buying local helps.

[richmanpoman1]

Just saturated fats are the dangerous ones. I know that good fats HDL fats-the good ones are good for you. Avocados-are one of the best.So SOME fats, are healthy for you. I am on a low fat/salt/sugar/carb diet, & am eating mostly veggies & mostly protein in the form of chicken, fish, whey powder, beans & eggs. The problem is when people stop one food (starches) & think they can have mega amounts of another (meat/cheeseAtkins) it usually only works for so long, but eating mostly veg's is best.

[NuclearNympho]

LOL 15 meat eating people don't like this video...LOL

[itzzmido]

too much protein may  effect the kidneys thats all

[LibertyJedi]

Truth is always hidden by lies and people like this do a very good job of hiding it- Duke is one of the collective why does he say fat, carbs, protein??? If there is Carbs in there? thought that was the purpose of the test..... It's like saying bankers are the biggest thieves.... this is true but everywhere u will see that people say it is not.