How Trendy Diets Can Wreck Your Microbiome - And How to Prevent It

How Trendy Diets Can Wreck Your Microbiome

Following the latest diet trend is tempting if you’re looking to lose weight quickly. Fad diets may help you lose weight in the short term, however, eliminating entire food groups can wreak havoc on your gut, otherwise known as the microbiome.1

This is because the good bacteria that make up your microbiome need certain foods in order to support optimal health. These same foods can also help you to lose weight.

When you drastically change how you eat on a trendy diet, your digestive system doesn’t have a chance to catch up. This type of diet overhaul is not only difficult to adjust to, but it can also result in digestive symptoms like bloating, gas, diarrhea, or constipation due to its effect on our microbiome. 

So even though your initial goal with your diet was to feel amazing, you may find yourself feeling not so healthy after all. Learn what happens to your body and your gut when you follow these diets, what to do instead to minimize these side effects, and still achieve your goals.

What is the Gut Microbiome?

The gut microbiome involves the billions of microorganisms that reside in our digestive system. These “microbes” include bacteria, yeast, fungi, and viruses. Many aspects of our mental and physical health are dependent on the state of our microbiome, so there is plenty of incentive to keep it happy.2

Research has shown a healthy microbiome can play a role in immunity, digestion, mental health, weight, and even improve overall health and wellness. To achieve a healthier gut, you have to fuel the good microbes in your body so that they can thrive while simultaneously reducing the number of harmful bacteria.3

One key factor in supporting a healthy gut is the type of diet that you follow. 

How Fad Diets Affect Your Microbiome

Fad diets are inherently restrictive in nature, and therefore typically require you to eliminate certain foods. This may seem easy if you are a rule follower, but this can actually wreck your metabolism and the integrity of your microbiome.

High fiber foods are often restricted on popular diets like keto or low carb diets that are devoid of grains, starchy vegetables, or fruit. Fiber is considered a non-digestible carb, meaning it travels through the gut undigested and then is broken down by bacteria in the large intestine. 

Fiber is a primary fuel source for some of the healthiest bacteria in the gut such as Bifidobacteria and Lactobacillus, and studies have shown those who eat more fiber have higher levels of these health-promoting bacteria. Eating more fiber has also been associated with less long-term weight gain, a common occurrence on fad diets.4

Complex carbohydrates like oats, quinoa, and whole-wheat pasta are also restricted on many weight loss diets, but they are hardly the bad guy. Complex carbs are digestible carbs that help increase diversity in the gut microflora by fueling the good bacteria, supporting optimal health.5

On the contrary, too much fat in the diet can damage your gut. A research study was done on those following the keto diet, which is about 90% fat. Those following the diet had increased numbers of pro-inflammatory bacteria in their gut and decreased numbers of beneficial bacteria like Bifidobacterium.6

How to Lose Weight the Right Way

It is possible to lose weight and keep your gut happy at the same time - it just requires a bit of strategy. Here are a few tips to lose weight the healthy way:

Don’t try to change everything overnight. When you drastically change how you eat, this leads to unwanted digestive effects and is simply not sustainable.

Focus on abundance instead of restriction. Instead of focusing on what to avoid in your diet, switch your mindset to what to eat more of - fiber and complex carbohydrates in the form of fruits, vegetables, whole grains, and gut-friendly proteins like chicken, tofu, eggs, Greek yogurt, and cottage cheese.

Up your probiotic intake. Consuming probioticsregularly from food and supplements also supports a healthy microbiome, and are found in yogurt, kimchi, kefir, tempeh, kombucha, and miso soup.*7

A diverse diet is more sustainable, it promotes microbial diversity in the gut, and helps you to lose weight without unpleasant digestive effects. Cheers to feeling your best throughout your entire healthy eating journey!


  1. Leeming ER, Johnson AJ, Spector TD, Le Roy CI. Nutrients. 2019 Nov 22;11(12):2862. doi: 10.3390/nu11122862. PMID: 31766592; PMCID: PMC6950569.

  2. Lucas G. Microb Ecol Health Dis. 2018 Nov 30;29(2):1548250. doi: 10.1080/16512235.2018.1548250. PMID: 30532687; PMCID: PMC6282467.

  3. Shreiner AB, Kao JY, Young VB. Curr Opin Gastroenterol. 2015 Jan;31(1):69-75. doi: 10.1097/MOG.0000000000000139. PMID: 25394236; PMCID: PMC4290017.

  4. Cronin P, Joyce SA, O'Toole PW, O'Connor EM. Nutrients. 2021 May 13;13(5):1655. doi: 10.3390/nu13051655. PMID: 34068353; PMCID: PMC8153313.

  5. Tianming Yao, Ming-Hsu Chen, Stephen R Lindemann. FEMS Microbiology Ecology, Volume 96, Issue 9, September 2020, fiaa158,

  6. Lubin FD, Campbell SL. Epilepsy Curr. 2018 Nov-Dec;18(6):389-390. doi: 10.5698/1535-7597.18.6.389. PMID: 30568557; PMCID: PMC6278741.

  7. Hemarajata P, Versalovic J. Therap Adv Gastroenterol. 2013 Jan;6(1):39-51. doi: 10.1177/1756283X12459294. PMID: 23320049; PMCID: PMC3539293.