If I saw “MTHFR” on a license plate, I might wonder what the person driving the car was so angry about all the time. But actually, MTHFR stands for Methylenetetrahydrofolate reductase, an enzyme that breaks down the amino acid homocysteine, not the curse word that may have popped into your head at first glance.

The MTHFR gene is where the DNA code that prompts production of the enzyme lives. This gene is vitally important to your health because it controls how well the enzyme can do its job.

There are two common mutations of this gene that can take a toll on your overall health. When the MTHFR enzyme isn’t working as it should it may lead to big problems, including poor heart health, cancer, birth defects, mood disorders, inflammatory bowel disease… and weight gain.

Weight gain is one of the biggest complaints the women who come to see me have. Often, these women are doing everything they can to maintain a healthy weight, but sometimes feel like they’re fighting a losing battle.

While there can be many reasons for weight gain that occurs even when you’re eating healthy, exercising, and doing everything “right,” a MTHFR mutation is something to consider.

Let’s explore how MTHFR impacts health and its relationship to weight gain. Then I’ll give you some tips on how to manage a MTHFR mutation to reduce weight gain and maintain good health.

Why is MTHFR important?

While this enzyme is related to many important processes in your body, it’s best known for the ability to lower homocysteine levels in the body. Why does that matter?

Homocysteine levels have been connected to higher risk of heart attack, stroke, blood clots, and plaque on the artery walls, as well as disruption in fetal development and fertility. (Varga, et. al)

MTHFR also plays a role in manufacturing serotonin and dopamine, which have a large impact on mood.

A 2006 review of research found that a common variant in the MTHFR gene was associated with major depression, schizophrenia, and bipolar disorder. (Seshardi, et al.; Gilbody, et. al.). Other neurological conditions, including Alzheimer’s disease, have also been connected to MTHFR mutations.

Mutations of this gene have also been linked to Inflammatory Bowel Disease, Crohn’s disease and ulcerative colitis (Mahmud, N. et al.) More recently, experts have begun to explore the relationship that the MTHFR gene has on weight.

As you can see, one gene can have a wide impact on your health, including your ability to look and feel the way you want.

How MTHFR and Weight are Connected

When considering whether the MTHFR mutation may be behind your weight gain, there are some common clues you can look for, including abdominal fat accumulation, fatty liver, high blood pressure, obesity, slow metabolism, family history or weight issues, and inability to lose weight even with a healthy diet and exercise routine.

MTHFR is responsible for converting folate (vitamin B9) from food into its active form so the body can use it. Mutations will affect how much active folate is available in your body.

If your body can’t process folate into the usable form, it will store the non-metabolized folic acid and result in weight gain and difficulty losing weight.

A 2016 study found that rats fed a high fat diet and given excess folic acid had increased inflammation, lipid storage and weight gain as compared to rats fed only adequate folic acid that were fed the same high fat diet.

B vitamins are major players in energy metabolism. There are many different B vitamins, all with slightly different jobs to do, but if you are deficient in one, it can have an impact on the others as well. For example, B-12 is needed to metabolize proteins and fat. But it can’t do so without B-6 and folate. A properly functioning metabolism allows fats, proteins and carbs to be used instead of stored as fat.

MTHFR mutations can also lead to hormonal imbalances, particularly increased estrogen. When estrogen cannot be processed and eliminated effectively, weight gain can be incredibly difficult.

High levels of homocysteines also contribute to weight struggles, since these high levels cause fat to accumulate which impacts insulin levels. Insulin resistance is a big factor in weight gain and difficulty losing weight.

Genetics aren’t inflexible

You may be starting to worry that your genetics mean there’s no hope in your weight loss struggles. That couldn’t be farther from the truth.

While your genetic makeup does, as we’ve been discussing, impact how your body processes nutrients, we’ve come a long way since the days when genetics were considered the blueprint for your destiny.

The truth is, outside factors like food, environment, nutrient deficiencies, and stress on your body impact how your genes behave.

They’re like a power source, turning certain genes on and off and changing how they impact natural processes in your body. Even better, we now know that there are things we can do to balance out gene mutations and keep them from causing major problems. This is exciting for a whole lot of reasons!

This knowledge gives us personal control like never before. Instead of throwing up our hands and accepting your “fate,” you can actively take steps to give your body what it needs to thrive. Let’s talk about some of these steps now.

Combat weight gain with these steps

Weight gain and an inability to lose weight can be lifelong struggles for some women. With the following steps, you may be able to finally make progress on your weight goals – without fad diets or extreme measures.

Know what you’re dealing with

Step one is to determine definitively whether or not you have a gene mutation impacting your weight. That’s why, when I suspect this may be the case, I recommend a comprehensive gene test.

When you understand the weaknesses (and strengths) of your genetic make-up, you can find strategies to help your body function optimally.

A diet plan that works

Knowing your genetics allows you to find the individualized way of eating that will work best for you. You may need to eat a low fat diet, or low carbs, or you may thrive on a combination plan.

There’s no right answer – we are all unique individuals. There are, however, some general rules that I recommend everyone follow – especially those with the MTHFR mutation. These include:

  • Eat organic whenever possible to avoid pesticides and other chemicals in your food.
  • Avoid processed foods. Eat whole, natural foods instead. If you can’t pronounce something on the label, leave it on the shelf.
  • Eat foods that are naturally high in folate, including dark leafy greens. Try to eat at least one cup or more of these daily. There are plenty of options: spinach, bok choy, swiss chard and kale are just a few of the choices available.
  • Don’t forget to hydrate! Your body needs water to function at its best. If plain water just isn’t your thing, try to jazz it up a bit by infusing with fresh fruit, choose naturally flavored seltzer, or drink a lot of herbal tea. Caffeinated beverages and alcohol have the opposite effect, dehydrating your body, so avoid them as much as possible.

Choose supplements wisely

With all of the potential for nutrient deficiencies that impact how our genes are expressed, I highly recommend that everyone take a high-quality multivitamin as part of their daily routine. If you know that you have a MTHFR mutation, you can counteract the deficiencies that may result with targeted supplementation, namely Metafolin (5-Methyltetrahydrofolate).

A dysfunctional MTHFR gene won’t provide this active form of folate that is essential to good health and disease prevention.

My Multi Essentials formula already includes this important nutrient. If the vitamin you choose doesn’t, consider either changing the one you use, or adding 5-Methyltetrahydrofolate to your regimen.

Find a Functional Medicine Practitioner You Trust

Conventional medicine resists some of these solutions, primarily because practitioners simply don’t have the time to explore the root causes of symptoms.

All too often a prescription pad is the only solution they have to offer. And this is simply not effective! Prescription medications cover up the problem rather than solving it.

In functional medicine, taking the time to uncover root causes is what we do. It’s why we’re here! You deserve to work with someone who takes the time to listen, explore, and keep digging until your problem is resolved.

Your fate is in YOUR hands

For far too long, women have thought that there are things they simply can’t control when it comes to their health. I disagree wholeheartedly.

While you can’t change which genes you were born with, you can change the way your body responds to these genes. By paying close attention to your lifestyle choices, nutrient deficiencies, and the way you feel, you can shift course before small issues become gigantic problems.

I’ve seen an amazing difference in my patients when we explore their genetic make-up and the impact it may be having on their lives, and add 5-MTHF support when necessary.

Some of these differences include improved mood, resolution of fertility issues, and finally getting the weight they’ve struggled with – some for a lifetime – under control!

Learn to work with your genes instead of against them. It might be the best gift you’ve ever given yourself!



Mahmud, N, et al. 1999. Increased prevalence of methylenetetrahydrofolate reductase C677T variant in patients with inflammatory bowel disease, and its clinical implications. GUT An International Journal of Gastroenterology and Hepatology. URL: http://gut.bmj.com/content/45/3/389.abstract?ijkey=9baa2662aa69ca9baf30b4d7a83e5a7e87fcbd3b&keytype2=tf_ipsecsha.

Varga, E, et al. 2005. Homocysteine and MTHFR Mutations. Circulation. URL: http://circ.ahajournals.org/content/111/19/e289.full

Seshadri, S, et al. 2002. Plasma homocysteine as a risk factor for dementia and Alzeimer’s disease. N Engl J Med, 346:467-83.

Gilbody, S, et al. 2006. Methylenetetrahydrofolate Reductase (MTHFR) Genetic Polymorphisms and Psychiatric Disorders: A HuGE Review. American Journal of Epidemiology. URL: http://aje.oxfordjournals.org/content/165/1/1.short.