12 Bad Habits That Kill Your Metabolism

Kevin Gray
by Kevin Gray
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12 Bad Habits That Kill Your Metabolism

You may already suspect your metabolism slows as you age. According to research in the Public Health Nutrition journal, you’re right. In a review of data on energy expenditure, researchers found getting older is associated with progressive declines in basal metabolic rate. On top of that, many daily habits can drain your metabolism even further.

But you don’t have to go down without a fight. Cut out the below habits and watch your metabolism and energy levels improve.

Eating a nutritious breakfast is a great way to start your day. Because your metabolism slows during sleep, eating can fire it up and help you burn more calories throughout the day. According to Rush University Medical Center, “When you eat breakfast, you’re telling your body that there are plenty of calories to be had for the day. When you skip breakfast, the message your body gets is that it needs to conserve rather than burn any incoming calories.”

OK, so it’s about more than just eating something in the morning. If you grab a sugary donut or eat a muffin in the car, you’re setting yourself up to crash later. Instead, choose something with filling protein and fiber like eggs, Greek yogurt and berries, or whole-wheat toast topped with peanut butter.

Going from your office chair to your car to your couch can lead to a very sedentary routine. And sitting for extended periods puts your body into energy-conservation mode, which means your metabolism can suffer. According to the UK’s National Health Service, “Sitting for long periods is thought to slow metabolism, which affects the body’s ability to regulate blood sugar, blood pressure and break down body fat.”

Cardio is great, and it can quickly burn calories, but once you’re done running or cycling, your calorie burn quickly returns to normal. When you do HIIT and resistance-based workouts, however, your calorie burn stays elevated for longer as your muscles repair themselves. Per the American Council on Exercise (ACE): “Strength training is a key component of metabolism because it is directly linked to muscle mass. The more active muscle tissue you have, the higher your metabolic rate.” And, according to ACE, a pound of muscle burns an additional 4–6 calories daily compared to a pound of fat.


Protein feeds your muscles, promotes satiety, and is an important component to sustain a healthy weight. Eat too little, and you may have trouble building or maintaining muscle mass — and per the above, we know muscle’s importance to metabolism. Also, protein requires more energy to break down than carbs or fat, so you’ll burn more calories during digestion.

In a study published in The Journal of Clinical Endocrinology & Metabolism, researchers found drinking 500 milliliters of water (about 2 cups) increases metabolic rate by 30%, and that spike lasts for more than an hour. So, drink water throughout the day to stay hydrated, and you’ll get the added benefit of a boosted metabolism.

When stress levels increase, your body produces a hormone called cortisol. Cortisol leads to increased appetite, cravings for comfort foods, decreased desire to exercise and reduced sleep quality — all things that negatively impact metabolism. So, while you can’t always control your stress levels, managing stress can go a long way toward protecting your body’s internal fire.

If you eat sources of refined carbs like white bread or pastries regularly, it could be slowing down your metabolism. Research shows those who consumed the most refined carbs burned fewer calories and had higher rates of the appetite-stimulating hormone ghrelin than those who adopted lower-carb diets that focused on complex carb sources.

“Refined carbohydrates from the diet turn into blood sugar very quickly; blood sugar is used for energy by the body [but] if it’s not used for energy, it can quickly turn into fat stores,” explains Lee Murphy, RD, senior lecturer of nutrition at the University of Tennessee.

Carbohydrates are important for energy, but skip refined carbs in favor of fiber-rich, unprocessed carbohydrates such as sweet potatoes and other starchy vegetables and whole-grain bread or pasta.

According to research published in the journal Nutrients, people with the highest intake of milk, cheese, yogurt and other dairy products had the lowest rates of obesity. This is part of a growing body of research linking dietary calcium to improved regulation of energy metabolism.

Dairy products are sometimes known as metabolism boosters, in part, because they contain protein and calcium — both possibly helping maintain muscle mass while potentially promoting weight loss,” says Murphy.

Before you start eating dairy at every meal, Murphy cautions your calorie counts and fat intake should remain within recommended guidelines.

A small study found sleeping in a cool room — either leaving the air conditioning running in the summer or turning down the heat before bed in the winter — could increase levels of so-called brown fat, which burns calories to generate heat. The ideal overnight temperature, according to the research: a cool 66ºF (19ºC).

One bad night’s sleep is enough to leave you feeling sluggish, impair your cognitive processing, and make you more likely to overeat. String together several nights in a row — or a lifetime of inadequate sleep — and science shows decreased metabolism and hormonal imbalances may follow.

You already know ordering a burger and fries at the drive-thru adds a lot of extra calories, “but it could also cause your metabolism to slow to a crawl,” says Whitney Linsenmeyer, PhD, RD, assistant professor of nutrition at Saint Louis University and spokesperson for the Academy of Nutrition and Dietetics. While you might be more likely to reach for a higher-fat meal in times of stress, “the high-fat content takes more time to digest,” she explains.

This can slow down metabolism, while stress compounds the problem. In one study, women who experienced at least one stressor over the past 24 hours burned 104 fewer calories after eating a meal containing 930 calories and 60 grams of fat than those who were not stressed. The difference could add up to an 11-pound weight gain in one year.

Originally published January 2019, updated with additional reporting by Jodi Helmer

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About the Author

Kevin Gray
Kevin Gray

Kevin is a Dallas-based writer who spends the majority of his weekends on a bike. His less healthy pursuits can be found at Bevvy and Cocktail Enthusiast.


33 responses to “12 Bad Habits That Kill Your Metabolism”

  1. Avatar Major Bummer says:

    These seem like good points, all. I’m going to take minute and write down the headlines to remind myself going forward.

  2. Avatar usa anon says:

    Read the article while sitting at desk in front of puter and now I am worried. I can’t sleep. I need a muffin, then I will watch a movie on TV.

  3. Avatar Lady in chains says:

    Am I missing something? My article isn’t showing Bad Habits #1, 2 or 3.

  4. Avatar Fitness Newbie says:

    Good article, although somewhat discouraging to older folks. Could you do an article that would address supplements that also support increased metabolism to mitigate the effects of growing older, assuming you have decent diet and exercise regimes?

    • Avatar Beth Stone says:

      Embrace growing older. No supplement will change that fact. But, how you deal with it can make it a joyful experience. 🙂

  5. Avatar eclectic_reader says:

    It’s a bad article and you should feel bad for writing it. Let’s take the water thing. Drinking 500 ml of water did not raise metabolic rates for the whole day as you imply. I raised them for a half hour, resulting in about 20 extra calories. Was the study result replicated? No? Let’s move on. EPOC from HIIT is vastly overstated, and nobody can do proper HIIT for more than a half hour including warmup and cooldown. Most beginners can’t hit those zones in the first place. Cardio is king for total calories burned, and research shows that consistent aerobic training has a significant positive effect on basal metabolic rate too. Metabolic rates slow with aging only for the inactive. Most of the metabolic slowdown is due to lost lean mass from decades of sedentary living. The paper you quote shows exactly that – not a decline in BMR, but a decline in activity throughout life as shown by the reduction in PAL and TEE from sitting on their butts doing nothing.

    It would help if MyFitnessPal would stop allowing unqualified hacks to represent them.

    • Avatar Jason Langdon says:

      MyFitnessPal allows unqualified hacks to represent them because it generates hits, and shares on their website which in turn generates revenue. As long as people are responding in the comments and sharing, this crap will continue.

  6. Avatar Mathew Andresen says:

    Number 1 is BS. Far better to do intermittent fasting and skip breakfast.

    • Avatar Matt Surch says:

      That was my reaction too. I’ve been doing intermittent fasting for about a year, while training and competing at an elite level in cycling, and it has been a fantastic tool for regulating insulin sensitivity and thus, my metabolism. The ‘breakfast is the most important meal of the day’ thing is a myth.

      • Avatar john egan says:

        That depends on what you you ate for dinner the night before and what time you ate it.

        • Avatar Matt Surch says:

          Certainly, if this isn’t obvious, some experimentation with macros would make it so. I currently do one meal a day, completed by 14:00, then do a 1000cal or so ride inside – moderate effort – followed by a short (10 min) kettle bell session as my coffee brews at about 06:00, then hit the gym for about 20 minutes of focused work, still fasted, then eat. If I’m running low pre-gym, I split the meal in two, eating relatively light at about 11:30. With this stuff everyone has to experiment to figure out what works for them, we all process food in our own ways.

    • Avatar tno2007 says:

      Guys, instead of calling number 1 B.S… let’s rather say “if you are doing intermittent fasting” then of course you should skip breakfast.

      But there are people who is “not doing intermittent fasting” and for them, eating something in the morning also works.

      It just depends on which diet you are following. What the article did wrong was not mentioning intermittent fasting.

      • Avatar Mathew Andresen says:

        I said it was BS because the author states BS like this

        ” Because your metabolism slows down during sleep, eating can fire it up and help you burn more calories throughout the day.”

        Eating breakfast doesn’t fire up your metabolism, or help you burn calories all day (certainly not more so than actually just not eating).

        The key to loosing weight isn’t eating, it’s not eating. Should be obvious. You want to lose weight, eat less or not at all. If eating “fired up your metabolism” we would all be skinny.

    • Avatar Jeff says:

      When I skip breakfast it effects my strength training for the worse. I make it a point to eat breakfast so I can get better results. It is what works for me so do what works for you.

  7. Avatar Fatoog says:

    Truly, myfatnesspile should stick to counting calories rather than enable random members of the public spout ill-informed lifestyle advice under their aegis.

  8. Avatar Intermittent Faster says:

    No, no, no, no, no. Stop with this breakfast is the most important meal of the day nonsense. Do some research.

  9. Avatar Carlos Rosado says:

    Stop! I’m not looking into who wrote this or bashing them, but I noticed next to this article is an article about IF. Contradicting? Yes

    Anyway, skipping a meal or 2 meals has ZERO effect on your metabolism, if anything, one could argue it benefits it. Should remove this article IMO

  10. Avatar AC says:

    Bad Habit #1 is a myth that intermittent fasting has (thankfully) dispelled. In my opinion, the only people who should be eating 5 meals per day are finely tuned college, Olympic, and professional athletes (or if you have a job like a fitness model, or you’re Dwayne “The Rock” Johnson, etc.). They need the calories because they workout twice per day for at least 90 minutes each session. For me, who is 45 years old and does short 40-60 minutes MRT and HIIT workouts, I fast for 16-18 hours per day and eat 1 or 2 big meals per day, and maybe have a snack (if I’m even hungry). For 99% of us “normal” people who workout 3-6 times per week for an hour or less, eating 5-6 meals in a day is just piling food on top of food and not giving our bodies enough time to digest the food. If I have my last meal of the day at 1:30 pm, sure, I’ll have “breakfast” at 6:30-7:30 am the next day after being fasted for 17-18 hours…but probably not before I do fasted cardio 😉

    I love intermittent fasting. It has literally taken most of the stress of eating out of my life.

  11. Avatar Reinhardt says:

    What Protiene can I eat without consuming meat or fish?

    • Avatar Ingeborg Hawighorst says:

      First, consult a dictionary and learn how to spell things. Then read about macros and nutritional values of meat and fish and other stuff. Use a search engine. Google and read. You know, READ! If you still have questions, do visit some sites and check out the lay of the land. BEFORE you post your trite ignorance. Whatever you do, please don’t blurt out your totally naive question in the first site that you discover that permits you to post a comment without any qualifications. Have mercy on the fellow readers of that site. Just because you CAN post does not mean that you SHOULD post.

    • Avatar Jason says:

      Legumes. Protein shakes.

  12. Avatar Bart says:

    #1 is following the Standard American Diet. Your article says skip muffins, and instead have yogurt or wheat toast. All of these are roughly equivalent! They are ALL LOADED WITH SUGAR OR REFINED CARBS.

    Skipping breakfast is a great idea, BTW. Eating a low fat, calorie restricted diet WILL ALWAYS LOWER YOUR METABOLISM!!!

    • Avatar Mathew Andresen says:

      Agreed with most of it. But it doesn’t even have to be a low fat diet. You can also do a keto/low carb diet combined with intermittent fasting and calorie restriction

  13. Avatar Lindsey says:

    How can you leave out dieting and under eating? Eating less than you should definitely slows your metabolism! You need a plan to reverse diet! The more you diet, the worse you get at dieting!

    • Avatar Mathew Andresen says:

      The effects of metabolism slow down are WAY overrated, and more than balanced by a reduction in calories. Intermittent fasting and calorie restriction work. If you want to lose weight eat less, and less often

  14. Avatar Tricia Bateman says:

    So crazy making and confusing. I just finished an article basically preaching the exact opposite of this article for the same “issues” … I realize we are all different, and need to find what works for us today, and in 5 years when our needs change. I just wish one person with the knowledge, would take an ounce of genuine interest and assist a person to find the right choices for themselves. I truly have been my worst enemy by reading articles such as this, and more articles, and more articles with nothing but conflicting information. T

  15. Avatar Tricia Bateman says:

    So crazy making and confusing. I just finished an article basically preaching the exact opposite of this article for the same “issues” … I realize we are all different, and need to find what works for us today, and in 5 years when our needs change. I just wish one person with the knowledge, would take an ounce of genuine interest and assist a person to find the right choices for themselves. I truly have been my worst enemy by reading articles such as this, and more articles, and more articles with nothing but conflicting information. T

  16. Avatar Cutie Pie says:

    I don’t understand why everyone on here is so mean with their comments. This is supposed to be a place where beginners like me can get well informed and, honestly, I just felt uncomfortable. Also, I am a grazer and have always had a very high metabolism. I was always told that if you deny your body, it preserves and holds onto whatever fat and calories you do take in because it’s afraid of being starved. I’ve been exercising every morning for 60 min (45 cardio-15 strength) and then I do a 30 minute walk after dinner. With food I just had to rearrange my thinking into realizing that food is for living and that everything should be eaten in moderation. This has worked for me… I mean I am losing weight. I hope everyone does what’s right and what works for them and try not to get discouraged. God bless!

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