5 Common Myths About Metabolism, and the Truth Behind Them

“Boost your metabolism with this [food/supplement/diet] and burn fat faster!” The draw of an easier path to losing weight is tempting when, deep down, we know the truth: weight loss usually takes time, persistence, and deprivation of guilty pleasures.  

Exercise equipment companies, diet food brands, and yes, even some nutritional supplement manufacturers have a history of using this common desire for weight loss to sell us a “quick fix”. The truth is that our metabolism biology is not easy to manipulate and these gimmicks are rarely quick or a fix. 

While we are here to deliver a reality check, let us not be the bearers of bad news. Let us relieve you of the myths that have been holding you back. Achieving and/or maintaining a healthy weight may not be easy, but you may feel better knowing it’s not just you for whom the gimmicks haven’t worked.

MYTH #1 – Eat carbs before cardio

Carb-loading is a method of eating lots of high-glucose carbohydrates before a big race or intense exercise event. The idea is that you maximize your glycogen stores (stored glucose in liver and muscle tissue) for sustained energy throughout the event. 

Before you reach for the giant bowl of pasta, however, you should know there are specific methods to carb-load properly.  There are also several potential drawbacks, and this style of eating is unlikely to benefit your metabolism. It is also important to repeat, carb-loading is meant for endurance events, and should not precede your regular cardio workout. 

Metabolism facts behind the carb-loading myth

First off, if weight gain is a concern, carb-loading is not for you. Carb-loading before a race usually leads to a 1- to 3-pound weight gain, notes dietitian Nancy Clark [1]. For every ounce of stored carbohydrate, you also store around 3 ounces of water. Helpful for staying hydrated during a marathon; not great if you’re working out to shed some quarantine cookie weight.

Many carbohydrate-rich foods, especially the healthier options (think: brown rice vs. white), are also high in fiber. The last thing you want before a cardio workout is a bloated gut and abdominal pain. Fiber is the most likely food to cause gas in the gut, and too much fiber can also lead to diarrhea. 

Blood sugar spikes and crashes are another danger of carbs before cardio. When you eat carb-rich foods, insulin is released so that cells can take in a lot of glucose quickly. With so much fuel your cells can work really hard and you’ll feel full of energy… for a short time. 

When the glucose is gone from the bloodstream, it can be pulled from storage, but you will likely feel a sudden drop in your energy level, possibly with a side of dizziness or weakness. You need to consume more carbohydrates to battle this low blood sugar, which could be tricky if you’re out on a long run, swim, or ride.

Instead of carb-loading before exercise…

Focusing on your protein intake is better than simple carbs for sustained energy throughout your workout. Branched-chain amino acids (BCAAs) specifically, can be great fuel for a cardio workout. BCAAs can actually delay muscle glycogen depletion, stretching stored glucose out a little longer [2].

The current recommendation for protein intake is 0.8 g/kg of body weight/day and is estimated to meet the needs of most men and women over age 19. Unfortunately, this recommendation is not sufficient for those who take part in strenuous exercise regularly. 

Protein/amino acid intake for athletes must offset the oxidation of protein/amino acids that occurs during exercise. On top of that, you must have enough material (amino acids) available to build new muscle and repair the normal muscle damage caused by exercise [2]. When BCAAs are taken right before or during aerobic exercise, studies show the net rate of protein degradation decreases, allowing repair and building of new muscle [2]. 

Of course, getting balanced amino acids from high-protein food sources is a great option, but amino acid supplements are also a smart choice. Amino acid blends like BAM® Energy Powder can provide all of the BCAAs you need to support your workout without filling you up like a meal. 

MYTH #2 – Sleep can boost your metabolism

Too little sleep is bad for your health. Too much sleep is also bad for your health. Finding the perfect amount of sleep for your body and achieving it nightly is the best for your health… and it can be really difficult. Sleep deprivation can interfere with normal metabolism, and is associated with an increased risk of obesity [3,4], but is the equation as simple as more sleep, faster metabolism? Probably not. 

Metabolism facts behind the sleep myth

The science behind this myth is that people who are sleep deprived are more likely to consume too many calories. It makes sense that when you are up too late, or up too early, you are conscious of hunger that you wouldn’t be able to act on if you were sleeping. Also, eating high-calorie foods is an instinctual way to battle feeling tired, as glucose (sugar) provides cellular energy and wakes us up, if only for a short burst (see myth #1). 

Sleep is also an important factor related to mental health. Poor sleep can cause mental health issues, and mental health issues can cause poor sleep [5]. Depression, specifically, can cause symptoms of sleepless nights and fatigue/low energy during the day [5]. While this may not be directly related to your metabolism, it will likely affect when and how much you eat and exercise.  

Instead of expecting sleep to boost your metabolism…

You should still aim for healthy sleep regardless of its relationship with your metabolism! The American Heart Association has stated that an irregular sleep pattern, or one that varies from sleeping seven to nine hours at night, is associated with a long list of cardiovascular risks, including obesity, high blood pressure, diabetes (or poor glucose metabolism), hormonal imbalances, inflammation, and coronary artery disease [4]. 

Getting less than six hours appears to be especially hazardous to your heart health, as those who are sleep-deprived tend to have higher levels of stress hormones and inflammatory markers in their blood, which are also markers of cardiovascular disease risk [4].

You can practice healthy sleep hygiene by shutting down screens an hour before bed, preparing a cool, dark bedroom, and journaling or meditating to relieve stress before bed. If you are still having trouble falling or staying asleep, a calming nutrient blend like Metabolic Maintenance’s R.E.M. MaintenanceTM or a melatonin supplement may help to naturally set your brain up for rest. 

If you think your mental health may be playing a part in the quality of your sleep, try addressing that root cause. Approximately 70% of those suffering from depression have inherited a faulty MTHFR gene [6]. MTHFR codes for an enzyme that allows folic acid to contribute to serotonin production. 

You can have your genetics tested to see if a lack of enzymes could be responsible for low serotonin production in your body. Whether or not this is the case, you can start supplementing with L-methylfolate instead of folic acid. L-Methylfolate is the active form of folate (vitamin B-9) and does not require MTHFR gene activity to participate in serotonin production. This means it is an excellent form of supplementary folate for everyone, regardless of genetics.

MYTH #3 – Eating lots of little meals will help you lose weight

Several epidemiological studies have reported an inverse relationship between how often people eat and their body weight, leading to the suggestion that snacking throughout the day may help in the process of weight loss [7]. 

The problem with all of these studies is that participants self-reported the data. As no mechanism to explain this phenomenon has ever been described, it suggests that under-reporting of the amount of food eaten may be skewing the results. Due to the societal shame associated with overeating and obesity, under-reporting is much more likely than over-reporting. 

Metabolism facts behind the many meals myth

The most convincing evidence that debunks this myth are quantitative studies using whole-body calorimetry and doubly-labeled water to assess energy expenditure (metabolism) [7]. These studies have found no difference between snacking and gorging in terms of weight loss, energy expenditure, or metabolism [7]. 

The same is true for intermittent fasting at the other end of the meal-planning spectrum [8]. At the end of the day, caloric restriction is what helps us lose weight, not when we eat or how often we eat.

However, here’s some food for thought: when you eat until you feel FULL, your body must focus so much energy on digestion that it often leads to lethargy in the rest of the body. If two people eat the same number of calories, but one gorged them all in one sitting and one spread them throughout the day, who is more likely to get their daily exercise in? 

Similarly, if you fast all day and only eat a large dinner, your body goes without energy substrate until the time you should be winding down. Who is more likely to get a better night’s sleep: the person who only ate a large dinner or the person who ate steadily throughout the day?

Instead of eating many meals…

Listen to your body. Eat when you are hungry, and stop when you are no longer hungry. Plan meals and portions ahead so you don’t accidentally overeat out of boredom or distraction. Stock your kitchen, pantry, and lunch box with healthy choices that you actually enjoy. Waiting until you are desperate to eat will make you more likely to reach for something unhealthy. 

Know what’s in your food. Smoothies, for example, can be a healthy or really unhealthy breakfast choice depending on what’s blended into them. Greens, fruit, and a protein source like nut butter or powdered supplement (try Metabolic Maintenance’s Metabolic Detox® Complete) are great choices. Fruit-flavored (i.e. sugar-filled) yogurt, fruit juices from concentrate, or sweetened dairy alternatives, on the other hand, send your smoothie into mostly-empty-calorie territory.

MYTH #4 – An aging body is doomed for weight gain

Get ready for this one to sting a little… if you are gaining weight as you’re getting older, it’s not because you are getting older. It’s likely because you are slowing down. 

Metabolism facts behind the “slowing with age” myth

Less movement and less exercise mean reduced muscle mass and fewer calories burned throughout the day. The good news is that your metabolism has not slowed down! You just need to find ways to comfortably move your body more and choose nutrition that nurtures an aging musculoskeletal system.

There is a widely held belief that large fluctuations in weight during one’s lifetime can leave you with a changed, or slowed metabolism. This too is a fallacy [9]. Most likely, it is habits changing over time, not your metabolism. Even small, 100-calorie changes (like cream in your coffee) can lead to many pounds of body weight over time. It is so easy to misjudge how much we are consuming, or burning off when we don’t live in a metabolic chamber.

Instead of blaming weight gain on your age…

Know that you are not doomed! By taking care of your body (eating well, exercising, self-care, and healthy sleep) you can maintain the metabolism you have always had. 

It’s true that growing aches and pains can affect both our healthy habits and our mental health, causing many of us to become more sedentary as we get older. If you see those issues standing in your way, you could try reaching out to a physical therapist. They can recommend low-impact exercises to keep your muscles working in comfortable ways. 

There are certain nutrients that can also help with joint pain and inflammation such as curcumin, glucosamine, and chondroitin. SAMe is another nutrient available as a supplement that can both benefit your joints and serotonin production for a more positive mood. 

At the end of the day, there are no magic pills or miracle diets that will allow you to shed extra pounds while you sit on the couch. Wouldn’t that be easy? Metabolism (the way our bodies use the calories we consume) is fundamentally difficult to slow down or speed up [6]. If you are interested in losing extra body weight or maintaining your healthy size, the best things you can do are tried and true: eat healthy foods, count your calories, and exercise regularly. 

Remember that all processes in your body, including a healthy metabolism, do require specific nutrients. If you think there may be gaps in the nutrition that your diet delivers, nutritional supplements can help to maintain balance. Supplements should be supplementary, however, and should not be a replacement for healthful, whole foods. If you are considering a weight loss plan, please talk to your doctor to make sure your plan is safe, healthy, and free of metabolism myths. 

MYTH #5 – Your metabolism and your immune system are unrelated

All of our body systems are connected, but as it turns out, metabolism and immune cell function are very closely linked. Immune cell function, at least in part, determines metabolic rate, and cellular metabolism affects immune cell function [10]. 

Metabolism facts behind the “metabolism is an independent system” myth

Many hormones in the body change in response to an overload or deficiency in nutrition. Much of the role that fat cells (adipose tissue) play in the body is signaling about the body’s nutritional status. Tumor necrosis factor-alpha (TNF-α), for example, is a pro-inflammatory immune signal and is known to increase in cases of obesity and decrease following a weight loss [10]. It signals the immune system’s inflammatory response and plays a mitigating role in insulin resistance, the body’s attempt to defend against unnecessary sugar absorption in times of overnutrition. 

Leptin is another well-known hormone that is a cytokine produced by fat cells, with an effect on immune cells. The amount of leptin secreted by adipocytes is proportionate to the mass of fat in the cell. Therefore, obese individuals have higher leptin levels than those who are not obese, and those who are suffering from malnutrition have lower levels than healthy individuals. 

For the sake of homeostasis, leptin signals the hypothalamus to trigger a feeling of satiation, suppressing appetite, and increasing energy expenditure [10]. Leptin also communicates energy status to the immune system, playing a role in the development of hematopoietic cells (which produce red blood cells) and cell-mediated immunity (including phagocytosis, cytokine production, and the number and function of T cells) [10].

 Leptin deficiency can lead to a compromised immune system, while an overload of leptin may lead to unnecessary inflammation and an overactive immune system, which can also be unhealthy.

On top of all that, think about how much exercise you’re likely to get done if your body succumbs to a cold or flu… Probably not much.

Instead of ignoring your immune health when focused on weight loss…

If you are concerned about your metabolism and your energy levels, be sure to take care of your immune system as well. Essential antioxidant vitamins like C, E, and A are a great start, as these immune-boosters clean up and prevent damage caused by free radicals and inflammation. Vitamin C can actually help reduce the severity and duration of cold symptoms and vitamin A is necessary for functional mucosal barriers and immune cell function [11,12]. 

Vitamin D is another important vitamin for immune function, and many people have developed deficiencies due to a lack of unprotected sun exposure. Most immune cells in the innate immune system express vitamin D receptors, supporting its biological necessity, and infection-fighting antimicrobial proteins are also often vitamin D-dependent [13].

There are lots of plant extracts and other nutrients that have science-backed immune-supportive activities as well. Check out Metabolic Maintenance’s Acute Immune Boost for a heavy-hitting blend of immune support ingredients. The dose of this formula can be adjusted so that it works as a daily supplement over the long term, or as a one-two punch for serious immune protection at a time of viral threat (air travel, flu season in the office, etc.). 

References

  1. Samuels, Mike. “What Are the Disadvantages of Carbohydrate Loading?” SF Gate. December 17, 2018. https://healthyeating.sfgate.com/disadvantages-carbohydrate-loading-11734.html
  2. Campbell, Bill, et al. “International Society of Sports Nutrition position stand: protein and exercise.” Journal of the International Society of Sports Nutrition 4.1 (2007): 8.
  3. Sharma, Sunil, and Mani Kavuru. “Sleep and metabolism: an overview.” International journal of endocrinology 2010 (2010).
  4. Harvard Health Publishing. “A good night’s sleep: Advice to take to heart”. Harvard Medical School. September 2017. 
  5. Newsom, Rob. “Depression and Sleep”. Sleep Foundation. September 18, 2020. https://www.sleepfoundation.org/mental-health/depression-and-sleep
  6. Shelton RC, Sloan Manning J, Barrentine LW, Tipa EV. Assessing Effects of l-Methylfolate in Depression Management: Results of a Real-World Patient Experience Trial. Prim Care Companion CNS Disord. 2013;15(4):PCC.13m01520. doi:10.4088/PCC.13m01520
  7. Bellisle, France, Regina McDevitt, and Andrew M. Prentice. “Meal frequency and energy balance.” British Journal of Nutrition 77.S1 (1997): S57-S70.
  8. Halpern, Bruno, and Thiago Bosco Mendes. “Intermittent fasting for obesity and related disorders: unveiling myths, facts, and presumptions.” Archives of Endocrinology and Metabolism 65 (2021): 14-23.
  9. Bulluz, Julia. “What I learned about weight loss from spending a day inside a metabolic chamber.” Vox. Sept. 4, 2018. https://www.vox.com/2018/9/4/17486110/metabolism-diet-fast-weight-loss
  10. Alwarawrah, Yazan, Kaitlin Kiernan, and Nancie J. MacIver. “Changes in nutritional status impact immune cell metabolism and function.” Frontiers in immunology 9 (2018): 1055.
  11. Rondanelli, Mariangela, et al. “Self-care for common colds: the pivotal role of vitamin D, vitamin C, zinc, and Echinacea in three main immune interactive clusters (physical barriers, innate and adaptive immunity) involved during an episode of common colds—Practical advice on dosages and on the time to take these nutrients/botanicals in order to prevent or treat common colds.” Evidence-Based Complementary and Alternative Medicine 2018 (2018).
  12. Armas, Laura AG, Bruce W. Hollis, and Robert P. Heaney. “Vitamin D2 is much less effective than vitamin D3 in humans.” The Journal of Clinical Endocrinology & Metabolism 89.11 (2004): 5387-5391.
  13. Chesney RW. “Vitamin D and The Magic Mountain: the anti-infectious role of the vitamin.” JPediatr (2010) 156:698-703.