Dr Will Bulsiewicz. Eimele Expert Gastroenterologist

When it comes to weight loss, everyone has that friend or family member. You know the one I’m talking about. They’ve tried it all — the latest diet, the top exercise trend, even forgoing the rules altogether. And nothing seems to happen. Heck, maybe that person is you and you find yourself wondering: “Why is losing weight seemingly so easy for some people and absolutely impossible for others?”

Let’s break it down starting with genes. Even though several genes have been implicated in the determination of body weight, this genetic susceptibility only explains a small fraction of obesity and doesn’t explain the explosion of obesity worldwide. The good news? It’s not a factor that’s out of our control. In fact, it appears there’s an environmental influence that explains the obesity epidemic, and it’s one that especially doesn’t come as a surprise to me given my day-to-day practice with helping people achieve better gastrointestinal health.

That’s right: I believe the answer to a lack of weight loss progress is in the gut. Don’t believe me? Let me share this story, as crazy as it might sound.

Back in 2006, a laboratory researcher named Dr. Peter Turnbaugh conducted a study using mice that forever changed the way we think about our gut microbiome. A total game-changer, you might say. In this study, Turnbaugh and fellow researchers transplanted the microbiota from both skinny and obese mice into otherwise germ-free mice, meaning the mice were raised completely sterile, so they didn’t yet have a microbiome.

When they did this, they were shocked by what followed. All of the mice were fed the exact same thing — same feed, in the same amount, yielding the same number of calories. There were no differences between the two, and all of the animals ate what they were fed. In other words, no one was skipping meals. But after just two weeks, researchers discovered that the recipients of the obese microbiome gained more weight and had more fat than the recipients of the lean microbiome.

The moral of the story (or, in this case, study)? The old age that tells us weight loss or gain is about calories in, calories out, isn’t exactly correct. On the contrary, our microbiome also has a lot to say about how to handle those calories.

Interesting, right? But now you’re probably wondering how to take the bull by the horns and get our gut microbes to work for us, rather than against us.

OK, here’s where I let you in on one of my favorite secrets. It’s all about short-chain fatty acids, or SCFAs. Basically, SCFAs clean up our gut microbiota, no matter how messy it

may be. They strengthen the good gut microbes, weaken the bad ones, fix the holes in our gut that cause “leaky gut” and reduce inflammation. According to a 2014 study, SCFAs also trigger the hormones that make us feel full, which is an underrated and very important part of maintaining our proper energy balance, by avoiding overeating.

So, how do we access these magical SCFAs? Well, my friends, there is only one place and the answer is from prebiotic fiber. (That is, of course, after you ingest it, it reaches your colon and your gut microbes chow down on it.) This explains why in a recent study published in The Journal of Nutrition, researchers discovered that one variable far outweighed the others in predicting successful weight loss — dietary fiber intake. In fact, regardless of macronutrient and caloric intake, dietary fiber intake was the number one factor in promoting weight loss.

Which is where we get to the part where I tell you how to add prebiotic fiber to your diet. Well, plants have cornered the market on fiber. You won’t find fiber in meat, eggs or dairy products. However, in addition to plants, you can also find fiber in Eimele Meal Replacement Sachets, including a Wild Mixed Berries Porridge. Want to take it up a notch (and, really, why wouldn’t you)? Boost your Eimele with a healthy sprinkle of plant toppings and you’ll be checking “drop stubborn weight” off of your list.

And this time it will be for good.