Why restrictive diets don’t work for gut health

What if I told you that these restrictive diets can actually harm you more than they are benefitting you? We’ve all fallen for dieting schemes. Claims like “feel and look better in 7 days” and “lose 10 lbs. in a month” have lured us in and forced us to deprive ourselves of foods we love. 

I have seen so many patients suffer from digestive issues after doing restrictive and fad diets. As I’ve mentioned in past posts, this method of dieting can have lasting effects on the microbiome which, if you’re new here, is the golden ticket to physical and mental health. In fact, restrictive diets may lead to a disease-promoting microbiome. 

Some of the most detrimental of these diets are the low carbohydrate diets – Keto, South Beach, Atkins, juicing alone and, to an extent, Paleo. All of these diets rely on the avoidance of different forms of carbs and high fiber foods such as legumes, grains, fruits, and even some vegetables. 

The truth is, when we stop consuming these nutrient rich foods, we are actually depriving our bodies which is why this type of dieting is unsustainable for long-term weight loss and health. 

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How diets harm your gut 

So, what exactly is the gut microbiome? Our guts hold about 39 trillion microorganisms, including viruses, bacteria, fungi, archaea (single-celled organisms) and microbial eukaryotes. These organisms evolved alongside us. They have adapted to survive inside our gut. The easiest way to envision it is to imagine the planet we live on. Our Earth is incredibly diverse, consisting of many different environments like deserts, swamps, and forests. It’s important to keep these ecosystems in balance. Every plant and animal living contributes to keeping the place in order and thriving. Our body, especially our gut, is very similar! 

What we eat, our microbes eat. If we stop eating legumes, then the microbial communities digesting them are starved and die off. These microbes are essential for many functions in our bodies. 

Our microbiomes act as a “second brain” and play a role in almost every aspect of our physical and mental health. By starving them, we are pushing ourselves to the edge of a health cliff and increasing our risk of all sorts of health issues such as inflammatory and autoimmune conditions, metabolic issues, and definitely digestive issues.

Digestion and low carb diets

Carbs are an essential nutrient. They provide our microbiomes with fiber. Then, it’s converted into an energy source to maintain the integrity of the colonic wall. This prevents harmful pathogens and toxins from entering our bodies. Carbs also help your microbiome to create short chain fatty acids which regulate inflammation.  

Yes, limiting your intake of donuts or white bread might be advised, but by avoiding healthy, whole carbohydrate foods, like quinoa and whole grain oats, you will deprive the microbiota of energy and starve it. To add to this, a lot of low carb diets like Keto are focused on fats. By eating significant amounts of animal protein and foods high in fat, you are further starving the microbiota and causing an imbalance in your gut. 

Low fat, moderate fat vs. high fat

In a study published in the British medical journal in 2018, researchers split 217 healthy 18 to 35-year-olds of normal weight into three dietary groups by altering the ratio of carbs– white rice and wheat flour–and fat–mostly soybean oil–but otherwise, keeping fiber and protein content the same. The three diets were: low fat (equivalent to 20 percent of energy intake), moderate fat (equal to 30 percent of energy intake) and high fat (accounting for 40 percent of energy intake.) They followed this diet for 6 months.

The results? The numbers of beneficial bacteria that produce short chain fatty acids, including butyrate, had increased in the low fat diet group. The higher fat diet was associated with significant and potentially detrimental changes in long chain fatty acid metabolism. This resulted in higher levels of chemicals that are thought to trigger inflammation. Although this study didn’t specifically follow a ketogenic diet and all groups had the same fiber and protein intake, it highlights the effect of a high fat diet on the gut.

The bottom line is that fad diets put a bandaid on a much bigger issue. They are focused on losing weight fast but not on getting to the root of what is really causing weight gain and fatigue–a gut imbalance. These methods are not sustainable which is discouraging and impacts people’s confidence and mental health. 

The solution: focus on what you’re eating

Dieting culture has trained people to negatively associate healthy eating with feeling restricted and defeated. By focusing on optimizing gut health instead of numbers on a scale or immediate gratification, we can change this and help people to develop healthier relationships with food. 

Stop focusing on what you can’t have when pursuing a healthy lifestyle and focus on what you can. Making it a priority to add fresh fruits, vegetables and other plant-based foods into your diet puts a positive outlook on healthy eating. 

There is no quick fix when it comes to health. Truly healthy living starts from the choices we make every day to nourish and heal our bodies.

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