Why some people gain weight eating the same food | Dr Karen Corbin

What if weight gain isn't just about how much you eat, but how much of your food your body actually absorbs? Is it possible that two people can eat the same meal with the same number of calories, yet one extracts more usable energy than the other? Not because of willpower, not because of discipline, but because of their gut microbiome. Today's guest, Karen Corbin, is a registered dietitian and scientist working at the cutting edge of nutrition, metabolism, metabolic health, and the gut microbiome. In this episode, we separate what's solid from what's speculative, unpack how the microbiome fits into all things energy balance and weight gain, and explore what's coming down the pipeline in this incredibly fascinating area of science. It does get detailed at times, but alongside this deeper science, Karen also shares practical evidence based takeaways for building a healthier microbiome. Okay. Let's get into it. Karen, is it possible that someone who's gaining weight or perhaps having trouble losing weight is actually absorbing more calories from their food because of their gut microbiome? It is possible. And if that's if that's true, what are the the implications of this for human health for explaining today's chronic disease rates and and perhaps how we may prevent or treat conditions like type two diabetes, for example? I think the most concrete way to look at that is think about when you look at a food label on a package of food, it tells you a number of calories. But those calories are entirely based on the human side of the metabolism equation, and they don't take into account the variable amount of energy that you could absorb once the foods that are not digested and absorbed in the small intestine make it all the way down to the colon where the community of microbes that resides down there has the chance to ferment them and make, energy basically out of those undigested foods. So we make this super practical. Let's say, you and I go in and and buy something from the grocery store. We buy the exact same product, and we eat the same amount, let's say, 100 calories of that food. It might be that I absorb more of of those calories than you do, and therefore, I have greater potential for storing fat and accumulating excess body fat over time. That's right. You might absorb 97, and I might absorb 82, which doesn't sound like a lot. But if you think about the cumulative effects of that differential absorption across many, many different foods, then it could add up. Is this a a new, you know, novel understanding that we've only kinda come to to learn over the last five, ten years? Or how long have scientists been aware of this? So I personally became aware of it around 2004 when the first publication came out showing that in rodents that didn't have a gut microbiome, they absorbed fewer calories. But the translation of …