Weight Loss Science Fiction: The Paleo Diet
You, yes you! Put down the Big Mac, come on you can do it. Now, let’s get back to our roots. It’s time to go hunter gatherer on your ass. In fact, you might as well dust off your loincloths and pull out your clubs, because paleo here we come.
Now it should be no surprise to anyone who has read any of my diet posts, I am a huge PETA fan. No, not that PETA, the People Eating Tasty Animals kind, what can I say, I love meat. Even if it is murder, it is tasty, tasty murder. I have also already expressed my disdain for Atkins, because let’s face it carbs are tasty too. However, today, we are talking Paleo and [big surprise] there is a lot of hype over something not so great.
First, the biggest problem I have with the paleo diet, it is not accurate. No really, despite the namesake, early man did not eat a “paleo” diet. However, don’t take my word for it; TEDx had a lovely talk about this with an actual paleontologist.
Like many diets, it makes outrageous claims. Why not, most diets need to promise miracles these days to be noticed. Thankfully, science is always standing by to test theories. It won’t stop people from making the claims, but at least the truth will be there for anyone wanting it.
With that, a new study helps poke some holes in those paleo diet claims. Specifically the claim that eating like a new age caveman [or woman] will make you feel fuller. By comparing how gut microbes from human vegetarians and grass-grazing baboons digest different diets, researchers have shown ancestral diets [like the paleo diet], did not result in better appetite suppression.
While Western diets have changed dramatically in the last century [can we say fast food?], our digestive systems — including our gut bacterial colonies, or the stuff that digests foods we eat — have adapted right along with us.
I have touched on glucagon, insulin’s evil twin so to speak. Well there is another peptide like glucagon, called [you might have guessed it] glucagon-like-peptide-1 [GLP-1] and another related peptide, peptide YY [yes, it is really named peptide YY, or just PYY]. Those hormones can be triggered by the presence of short-chain fatty acids [SCFAs] in the colon.
[Loony Hint: A peptide is just a short chain of amino acids. If it wasn’t obvious, enough, short-chain fatty acids are just that. Short-chains of fatty acids, fatty acids being the technical term for fat and the length of that fat is short.]
Those two hormones are responsible for the feeling of satiety [or being full]. As it turns out, the digestion of a diet in high plant fiber also produces SCFAs. So would make sense that digestion of a diet high in plant fiber might lead to better appetite suppression.
The team established gut bacteria cultures in flasks and then ‘fed’ those two different diets—either a predigested potato, high-starch diet or a predigested grass, high-fiber diet. Then they tracked changes in the numbers and types of bacteria and measured the metabolites produced by digestion.
As it turns out, the human cultures on a potato diet produced the highest levels of SCFAs. Even the baboon cultures fed potato produced more SCFAs than the baboon cultures fed grass. When the researchers applied some of these cultures to mouse colon cells in the lab dish, the cells were stimulated to release PYY hormone. Those exposed to human cultures digesting a potato diet released the most PYY, followed by those exposed to baboon cultures on a potato diet.
This evidence argues that the previous view of paleo diets and appetite suppression is flawed and that high-fiber, plant-based diets likely do not lead to increased SCFAs and increased appetite suppression. Rather, the researchers propose, little to no appetite suppression might actually help baboons maintain grazing all day to consume enough nutrients.
But it gets even better, closer cataloguing of all the metabolites produced by the bacterial cultures digesting potato or grass diets showed that as the levels of the amino acids isoleucine and valine rose, so too did the amount of PYY released. This relationship was even stronger than that with SCFAs.
“This hints that protein might play a greater role in appetite suppression than the breakdown of starch or fiber,” said Timothy Barraclough, a co-author of the study. “More work will be needed to explore the effects of alternative breakdown products of various foods.”
So you want the truth about the paleo diet.
It’s claims are overblown, it is overly restricting, and it doesn’t live up to its namesake. As with any diet, if you feel happy about cutting certain types of food out of your diet, then maybe the paleo diet is for you. If you would prefer to enjoy life and eat anything that it has to offer, well then I would avoid, yet another fad diet and stick to moderation as a lifelong approach to weight loss instead.
[Loony Hint: These findings are not contradictory to the claims I made in the first post on fat loss, we are talking about two different kinds of fiber, insoluble fiber will typically aide in satiety, not that it was the primary claim I was making.]
Frost G.S., Barraclough T.G., Gibson G.R., Walton G.E., Sponheimer M., Johnson L.P., Costabile A., Swann J.R. & Psichasa A. (2014). Impacts of Plant-Based Foods in Ancestral Hominin Diets on the Metabolism and Function of Gut Microbiota In Vitro, American Society For Microbiology , 5 (3) DOI: 10.1128/mBio.00853-14