Every week, I talk to people in my Reset Academy who say that, after years of struggling, they’re finally losing weight. Most of them tried calorie counting in the past and it didn’t work—but intermittent fasting does.
A 2022 review found the same thing. After looking at 11 studies and more than 700 participants, it concluded that fasting is better than low-calorie dieting when it comes to weight loss—and, crucially, people who fast are better at keeping weight off long-term.
Why is that? What makes fasting different?
According to a new study, part of it could be how fasting changes your gut bacteria.
The study was published in the journal “Nutrients” and is titled Time-Restricted Feeding Modifies the Fecal Lipidome and the Gut Microbiota. We’re going to take a closer look at it, because it offers some very cool insight into why fasting is so good for weight loss.
Here’s what the latest research says about fasting and weight loss, and how you can use fasting to get in the best shape of your life.
New Study: Fasting Changes Gut Bacteria (and Helps with Weight Loss!)
Before we start: this new 2023 paper is in mice, not people. Normally I wouldn’t make a big deal out of animal study. We’re not mice, after all!
But this study is exciting because it explains a lot of recent human fasting research. We know from human studies that fasting is good for weight loss, and that it changes your gut bacteria. This is the first paper to link the two together, which makes it especially cool.
In the study, researchers put mice on one of three diets: a low-fat diet, a high-fat diet, or a high-fat diet where they could only eat at night, to mimic intermittent fasting. After 12 weeks, researchers measured the gut bacteria and fecal content of the mice.
Normally, mice become obese when they eat high-fat diets—which is exactly what happened to the high-fat group that could eat all day.
But the mice that could only eat high-fat food at night (and fasted during the day) didn’t gain weight. They stayed slim, despite eating a similar amount of total food as the all-day group. After sampling the mice’s gut bacteria and fecal matter, researchers believe they know why.
It turns out the mice who fasted had different gut bacteria than the high-fat diet mice, even though both groups were eating the same food and the only difference was meal timing.
Not only that, but mice who fasted at night had significantly more energy in their poop, which meant they weren’t storing calories the way the other mice did. They could eat the same amount of food, just in a shortened window, and they wouldn’t absorb the calories or gain weight.
The researchers concluded that fasting changed the mice’s gut bacteria in a way that helped the mice lose weight, even when they ate a lot of food.
What About Human Studies on Fasting and Weight Loss?
This study adds to a growing body of human research on fasting, gut health, and weight loss. Here are a few highlights:
- A 2021 study found that fasting increased healthy gut bacteria, especially bacteria that speed up your metabolism and promote longevity.
- Another 2021 study found that fasting led to weight loss and lower blood pressure in overweight adults. It also increased healthy gut bacteria.
- A 2020 review of 11 studies found that fasting is highly effective for sustainable weight loss. The review also concluded that fasting worked better than normal low-calorie dieting.
We’ve known for a long time that fasting is great for weight loss, but it’s only in these past few years that researchers have begun to understand how fasting affects your gut bacteria. The changes in your gut health seem to be positive—which is even more good news for fasting!
How to Start Intermittent Fasting Today
Fasting is an AMAZING tool for weight loss, mental clarity, longevity, increased energy, and more. Best of all, it’s easy to do, and you can start it right now.
My free Beginner’s Guide to Fasting has everything you need to start fasting right now. And if you love fasting and want to do it with a community, consider joining my Reset Academy. We’re a group of people who love getting in shape together, and we have weekly workouts, regular meetings to chat and drink coffee, exclusive Q&A sessions, and a whole lot more.
Fasting is one of the single best things you can do for your wellbeing. Give it a try—you may be surprised by how good it makes you feel!