So what exactly is metabolism? Mayo Clinic says it's "the process by which your body converts what you eat and drink into energy. During this complex biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function." And while a slow or fast metabolism is not the main reason you're gaining weight or losing weight, a disruption in your metabolism can make it harder to burn calories.
To figure out what can mess with your metabolism, we turned to nutritionists for advice on the things that could throw it off-balance. It's important to note that you can make a few tweaks here and there to boost your metabolism, but it won't be the only answer if you're looking to lose or maintain your weight. It always comes down to the basics: "The overall quality of diet and lifestyle plays the most important role in our overall health—from how we process and digest food to how it is utilized in the body to how it affects our overall health and risk of metabolic diseases in the long run," says Alicia Romano, a registered dietitian and nutritionist and a national spokesperson for the Academy of Nutrition and Dietetics.
Yes, you read that right. But no, that doesn't give you free rein to eat endless desserts. "We all think the less we eat the more weight we’ll lose," says Amy Shapiro, MS, RD, CDN, founder and director of Real Nutrition. "However, not eating enough may lower our metabolism. Our body needs adequate calories to maintain our energy burn, and when we short-change it, our body naturally slows its burn to reserve the energy stores that it has. So when you eat enough calories, your body doesn't have to store or reserve, so we burn more efficiently."
Consistency is key here. "Not eating consistently can throw off your metabolism. (I encourage clients to eat every three to four hours throughout the day.) Eating smaller meals and keeping a regular eating schedule can keep the metabolism stable and healthy," says Yasi Ansari, MS, RD, CSSD, a national spokesperson for the Academy of Nutrition and Dietetics.
If you want to try intermittent fasting, Ansari recommends doing it for a day or two per week but making sure you meet your calorie needs on "normal" eating days and not eating less.
This makes sense when you think about the first watch-out above since many super-restrictive diets call for eating very little. "Many people put themselves on strict calorie-restriction programs to lose weight, but that actually does not benefit metabolic function most of the time," says holistic nutritionist and cleanse expert Elissa Goodman. "I recommend that most of my clients give their bodies the calories they need to function properly. If you are dieting too intensely, you can wind up entering 'starvation mode.' This causes hormonal and cellular changes that drive up your hunger and thirst while slowing down your fat-burning abilities and muscle growth. Your body slows down all of its essential processes as a means of conserving energy since it is not consuming enough fuel in the form of food."
Drastic diet changes can affect your metabolism, too. "Additionally, we do know that yo-yo dieting (i.e., dieting, regaining weight, dieting again, regaining weight), also known as weight cycling, may be associated with long-term risk of developing obesity and other metabolic conditions," Romano says. "The best approach to weight management? A balanced eating program that prioritizes quality food and lifestyle changes."
A good night's sleep is always the key for most things in life. "Research has revealed a connection between sleep and weight," Ansari says. "The exact mechanisms are still being studied. Insufficient sleep can alter hormones such as ghrelin (a hormone that increases appetite/hunger) and leptin (it tells us we're full, which decreases hunger). Studies have shown that sleep deprivation can alter glucose metabolism (decreased ability to break down glucose) and can affect hormones, leptin, and ghrelin (can decrease leptin and increase ghrelin). Those who don't get enough sleep are more likely to make food choices that are higher in fats and sugars, eat larger portions, and are more likely to make impulsive food-related decisions in hopes of boosting energy after a night of poor sleep."
Sleep deprivation can also affect the way your body processes food. "Lack of sleep may also impact insulin sensitivity," Romano says. "When your body becomes less sensitive to insulin, you are unable to properly use the food you are consuming, creating an opportunity for weight gain."
"Certain medications may impact your weight. For some, this may be related to a metabolic shift, and for others, it may be related to the way these medications affect our appetite and hunger hormones," Romano says. "Medications including antipsychotics, antidepressants, epilepsy medications, and steroids may be linked to weight gain. It is important to note that not all medicines of these types cause weight gain, and I would recommend speaking with your doctor about the potential side effects of any medication regimen." If you're experiencing unwanted weight gain as a side effect, Romano suggests talking to your doctor about any potential and appropriate alternatives and working with a dietitian on diet and lifestyle changes if needed.
Goodman offered some supplement recommendations that may have a positive effect: "Coconut oil and MCT oil are two of my favorites since they are so easy to implement and have some wonderful metabolism-enhancing properties. I often recommend that my clients add a spoonful of MCT oil to their morning coffee or smoothie to kick-start their metabolism for the day ahead. Coconut oil is one of my favorite oils to cook and bake with, and ginger has also been found to increase calorie-burning processes."
You don't have to say goodbye to steamy showers, but a jolt of cold water might do your body some good. "One fun metabolism booster is taking cold showers. Not only does cold water force your body to work harder to keep you warm, thereby burning more calories, but it also activates healthy brown fat that helps to eliminate harmful adipose (white) fat. For optimal results, alternate 20 seconds of hot water and 20 seconds of cold water in the shower for a few minutes," Goodman says.
"Not eating a variety of foods can also throw your metabolism off-balance," says Ansari. "The goal is to be eating consistently, with all macronutrients (protein, fiber-rich carbohydrates, and heart-healthy fats). Protein is a big one: Eating protein at each meal can boost metabolism. (I generally recommend getting at least three to four ounces of protein at each meal.) The thermic effect of food (increases in metabolic rate when eating a meal) is higher when consuming protein, causing the body to expend more energy while chewing and eating. Goal? Eat a variety of whole foods at each sitting, and make sure you have adequate protein at each meal/snack sitting."
And you'll want to stay away from overprocessed food: "We know that a diet abundant in highly processed foods (refined carbohydrates, added sugars/sweets) may also be linked to increased insulin sensitivity. When your body becomes less sensitive to insulin, you are unable to properly use the food you are consuming, creating an opportunity for weight gain," Romano says. But she also adds that a sweet treat in moderation won't totally wreck your metabolism, and it all comes down to, you guessed it, a balanced overall diet and lifestyle quality.
Yet another reason to get a sweat session in. "Not working out enough can decrease metabolism. Gaining fat-free mass (FFM) after exercise can help increase the BMR (the number of calories required to keep your body functioning at rest)," Ansari says. "It is important to note that muscle is far more metabolically active than fat. Typically, more muscle can burn more calories."
This is especially important as you grow older, when your metabolism starts to slow down. "There is also about a 2% to 3% BMR reduction per decade that is observed for both adult men and women," Ansari says. "This is likely due to changes in body composition, either a decrease in FFM and or an increase in body fat during adulthood. According to one study, resting metabolism increased by 8% when 50- to 65-year-old men increased their FFM with resistance training. Another study found aerobic training programs for older individuals also boosted metabolism independent of gains in FFM. This suggests that taking part in physical activity, whether aerobic or resistance training, can boost metabolism, which can combat decreases caused by aging."
As for how much exercise you should get, Romano says the general recommendations to start with are 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity weekly.
You might plan on working out more after reading number seven on the list, but if you're only doing cardio, you might not be optimizing your workouts. Shapiro suggests adding resistance training to the mix: "As we age (over 30), we slowly start to lose muscle mass, so resistance and/or weight training is an important type of exercise to incorporate, as it helps to maintain muscle mass. The more muscle mass we have, the higher our metabolism, as muscles burn more calories than fat. Cardio is great, but it doesn’t increase our metabolism. And no, you won’t bulk up from weight training. However, you might if you don't!"
This can be a factor, especially when it comes to your sleeping habits during the trip. "Frequent travel can affect metabolism if it disturbs your sleep cycle. Additional studies are needed on long-term effects of frequent travel," Ansari says. "However, circadian misalignment (defined as a variety of circumstances such as inappropriately timed sleep and wake, misalignment of sleep/wake with feeding rhythms) can affect appetite-stimulating hormones (leptin and ghrelin), glucose metabolism, and mood." When traveling, she suggests adjusting your sleeping and eating habits to adapt to your destination.
This article is provided for informational purposes only and is not intended to be used in the place of advice of your physician or other medical professionals. You should always consult with your doctor or healthcare provider first with any health-related questions. See our full health disclaimer here.