Don’t you wish that you could boost your metabolism and finally lose weight, reverse diabetes, or just get better results from your workouts?
Read more to learn the five steps you can take to get a healthy and flexible metabolism that will allow you to achieve all of these goals!
What is a healthy metabolism?
Human metabolism comprises all of the biochemical reactions needed to convert energy from the food you eat into the energy required for all cellular functions and the activities of life. The human body strives to maintain a constant energy balance between intake and expenditure.
Total energy expenditure is the sum of the energy you need at rest for basic organ functions called basal metabolic rate (60%), the energy required for digestion and absorption of food called thermogenesis (10%), and the energy required for physical activity (30%).
Total energy intake, on the other hand, includes all of the calories you consume from macronutrients such as fat, protein and carbohydrates, and any calories consumed from alcohol.
When you eat and digest carbohydrates, your blood glucose level increases. In response, your pancreas produces insulin to move the glucose into the muscle cells to be used for physical activity or stored as glycogen for future energy needs. If excess calories are consumed, they will be stored as fat.
During a fasting state, such as extended periods of time without food or overnight, your body will burn fat for fuel when glycogen stores are depleted.
A healthy metabolism is a flexible metabolism that can easily switch between burning fats and carbohydrates for energy in response to fuel availability.
Metabolic inflexibility is unhealthy and is caused by insulin resistance, which forces the pancreas to produce more insulin than normal after a meal. But even though insulin levels are higher, the cells are resistant to insulin, so it is less effective in moving glucose into the cells for energy. So in the fed state, fewer carbohydrates are burned for energy. Moreover, the higher insulin levels prevent fat burning during fasting and promote the storage of fat.
When peripheral fat cells reach their capacity, excess fat is stored in the liver and muscles, causing lipid toxicity, which increases insulin resistance. Diets that are high in fat and in branched chain amino acids from animal proteins are associated with “metabolic gridlock” and can prevent fat burning. Insulin resistance leads to a chronic low-grade state of inflammation and the metabolic syndrome which increases the risk of many health conditions.
Physical activity increases metabolic flexibility
According to research at the University of Colorado, regular physical activity is the primary determinant of metabolic flexibility. It’s important to have a flexible metabolism to decrease the risk for obesity, type 2 diabetes, cardiovascular disease and certain cancers.
A study published in The Lancet, a top medical journal, reported that 9.4% of deaths worldwide can be attributed to low physical activity levels, which harms health as much as smoking and obesity does. Daily sedentary time of more than 6 hours is a distinct form of physical inactivity that harms metabolism, even in those who meet the current guidelines for physical activity of 150 minutes per week.
Exercise increases fat burning in muscle cells and decreases fat storage in adipose tissue. The contraction of muscles during exercise increases the intake of glucose by muscle cells independently of the action of insulin. Regular aerobic exercise increases the number of muscle mitochondria, the organelles that burn fat and glucose for energy, while resistance training increases muscle size and glycogen storage capacity so you can consume more carbohydrates for energy.
So, how much exercise does it take to see a change in metabolic flexibility? One study found that ten consecutive days of aerobic exercise (1 hour/day at 70% VO2 max) increased fat burning in skeletal muscle in obese individuals to the same extent as in lean people.
In summary, metabolic flexibility is a healthy, adaptive metabolic response to maintain energy balance by matching available fuel and the demand for it, under a variety of conditions such as meals of varying macronutrients, fasting, physical activity, and other environmental factors.
Consult your physician before making changes to your diet or physical activity levels, especially if you’re managing a medical condition. In the meantime, if you want to achieve a healthier metabolism, here are five actions you can consider.
Five steps to increase metabolic flexibility
- Go for a 20-minute walk in the middle of your workday. Breaking up sedentary time with physical activity improves metabolic flexibility, even in individuals who exercise regularly.
- Exercise aerobically for one hour daily at moderate intensity, and perform resistance training exercise two to three days each week.
- Eat a low-fat, nutrient-dense diet that allows you to achieve a healthy weight, and avoid calorie-dense, highly processed foods.
- Achieve a daily fasting state so that your body can deplete its glycogen stores and begin to burn fat for fuel. Try a time-restricted feeding schedule that includes 12 hours fasting after dinner from 7:00 PM until 7:00 AM, unless you have a medical condition, including pregnancy, hypoglycemia or you take blood glucose-lowering medications such as insulin.
- Shift the timing of your meals so that you consume more calories earlier in the day, even if you don’t reduce total caloric intake. This helps to reduce insulin resistance, which is tied to our circadian rhythm. Both growth hormone and cellular repair increase at night, while insulin sensitivity decreases overnight.
References:
Rynders, Corey & Blanc, Stephane & De Jong, Nate & Bessesen, Daniel & Bergouignan, Audrey. (2017). Sedentary behaviour is a key determinant of metabolic inflexibility. The Journal of physiology. 596. 10.1113/JP273282.
Lee, I-Min & J Shiroma, Eric & Lobelo, Felipe & Puska, Pekka & N Blair, Steven & Katzmarzyk, Peter. (2012). Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy. Lancet 380: 219-229.
Smith, Reuben & R Soeters, Maarten & Wüst, Rob & H Houtkooper, Riekelt. (2018). Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease. Endocrine Reviews. 39. 10.1210/er.2017-00211.
https://academic.oup.com/edrv/article/39/4/489/4982126
Battaglia GM, Zheng D, Hickner RC, Houmard JA. Effect of exercise training on metabolic flexibility in response to a high-fat diet in obese individuals. Am J Physiol Endocrinol Metab. 2012;303(12): E1440–E1445.
Goodpaster BH, Sparks LM. Metabolic flexibility in health and disease. Cell Metab. 2017;25(5): 1027–1036.
https://www.cell.com/cell-metabolism/fulltext/S1550-4131(17)30220-6