Your metabolism is responsible for the fuel your body needs to function. Food is broken down into energy (calories) for our bodies to run on, and excess calories are stored as fat. But can you improve your metabolism with diet and exercise alone, or are you doomed due to your genes?
Your body automatically burns freebie calories even before opening your eyes in the morning in the form of your basal metabolic rate (BMR). This is the energy requirements our muscles and other organs have while resting. But once you start moving around, eating, and thinking, your body needs more fuel in the form of calories (total caloric expenditure).
When it comes to weight loss, most people research ways to improve their metabolism. But keep in mind, genetics play a significant role, and could explain some of your struggles or plateaus. There are many factors that determine weight even outside of metabolism.
Diet, Lifestyle & Genes: Who’s to Blame?
Endocrinologist Kaitlin Love, MD, explains that genetics drive our weight more than we think. So, when trying to lose weight, you have a team of factors as to why you might be struggling. These include how our hunger and appetite hormones function, causing a tendency for increased food intake. Also, how well we absorb and store calories, the type of fat our bodies store, and metabolism, among others.
Many of these factors are outside our control. You can add more exercise and muscle mass to improve your metabolism. But much of what determines weight comes down to our gene makeup based on past generations. There are other factors which we have no say in, like our environment while growing in the womb and even during infancy and early childhood.
Researchers are still learning about genetic factors that determine weight. One common gene associated with a higher weight is the “fat mass and obesity" (FTO) gene. This gene seems to cause a predisposition for increased food intake and may be important for determining the type of fat our bodies store.
It’s not just from your mom or dad — your determinants of weight and metabolism go further back into a large gene pool. This is a scary thought for future generations as we’re becoming sedentary and eating processed foods daily. Our genes are learning to adapt to this new lifestyle, which will be passed along to our kids.
How Metabolism Works
Our bodies need a specific amount of nutrients to run. Protein, fats, and even carbohydrates are turned into calories for this fuel. When we follow trends such as the ketogenic diet and intermittent fasting, our bodies can compensate over time for a low-calorie diet.
Once you add an activity such as walking to the bathroom from the couch, your body adds additional calories to run our muscle cells. Other factors that play a role in your metabolism:
- Body size, especially lean mass
- Weight history
Men tend to have more muscle than females, which means they’re burning more calories automatically. You lose muscle mass as you get older, so your metabolism begins to slow down, and you burn fewer calories.
Your metabolism also remembers your weight history, a theory called “biological set point.” This is why you might plateau or gain weight again after a significant amount of weight loss. Your body can reduce your basal metabolic rate even lower than the calories it previously needed to drive you back to a higher weight, making it hard to lose weight.
A Chemical Reaction
Hormones also play into this sneaky behind-the-scenes energy machine. We’ve all had cravings or felt hungry even after eating. We're born with appetite hormones like leptin that decrease our appetite, and hunger hormones like ghrelin, which increase it.
Weight loss can also shift the balance of these hormones, increasing our hunger hormones, and decreasing our appetite hormones. If you’re struggling with weight loss, providers can prescribe neurohormonal medication to help this problem. Our bodies are so programmed to regain weight, multiple agents are usually most effective.
We can also blame stress and lack of sleep for contributing to weight gain due to the hormone cortisol. This is why shift workers tend to have weight issues as they have varying cortisol levels.
This lovely hormone works with your mood, motivation, and fear, best known as the body’s “fight-or-flight” mode. When you have large amounts of this hormone, your body begins to store more fat and increase food cravings. It also affects your blood pressure and blood sugar, and it is influenced by your sleep cycle.
What’s the difference between night-sleepers and day-sleepers if they’re all getting enough sleep? Most night-shift workers don’t get the best sleep during the day. And when they have days off, they want to socialize during the day, forcing their sleep schedule back to nights. This disruption of normal sleep-wake hours leaves a messy hormonal balance as well as promotes bad eating habits.
Love recommends eating at normal meal times during the day to make the cortisol system happy and help improve your metabolism. Intermittent fasting works for weight loss and is comparable to calorie-restricting diets, but try the 11 a.m. to 7 p.m. schedule first.
Your thyroid can mess things up, too. So, if you’ve been struggling to lose or gain weight, your provider may check your thyroid levels with a simple blood test.
Women and Big Life Events
Women want to bounce back to their former bodies after pregnancy. Because of the physiologic changes to tissues in pregnancy, it is normal to gain a few pounds after having a child. Major obstacles for weight loss for many new moms are also losing sleep and being busier than before. There tends to be less time for exercise and healthy food choices during this huge life stage.
Women going through menopause don’t need as many calories as they did before. Several factors contribute to this, including age, reduced muscle mass, and fewer activities. Reduction in estrogen levels after menopause also translates into changes in body composition (more abdominal fat), mood changes, and sleep disruptions. As you lose muscle mass, it lowers your total energy expenditure, making it easier to gain weight. The goal is to find a balance of calories that work for your body.
Need A Little Help?
Your provider can prescribe neurohormonal medication to help you with your weight-loss journey.
How Do You Improve Your Metabolism and Lose Weight?
Losing weight can be frustrating. Increasing your movement throughout the day will boost your total caloric expenditure. You need high energy expenditure to keep weight off. HIIT workouts (high-intensity interval training) have become more popular over the last couple of years, increasing the calorie burn in one workout. But any activity is good for you! Take a short, brisk walk before work or during lunch to boost your metabolism.
Your diet is most important for weight loss, so monitor your calorie intake, and find a diet, or better yet, a lifestyle change, that is sustainable. But there’s no secret food that will stimulate and improve your metabolism.
Love offers some other tips:
- Avoid liquid calories, especially those with no nutritional value, such as sodas and alcohol.
- Eat smaller, more frequent meals so you won’t overeat at dinner. People who eat larger breakfasts tend to eat fewer total calories throughout the day compared to people who skip or eat light breakfasts.
- If you are attempting weight loss, aim for a minimum of 150 minutes of moderate-intensity exercise per week. This could be a brisk pace at which you would walk if you were late for a meeting. This is particularly important to maintain weight loss and very important for cardiovascular health and preventing diabetes.
- Curious about what your BMR is? You can find a BMR calculator with a quick online search. Most food tracking apps that ask for your weight and height have an accurate calorie daily intake.