Since our goal in losing weight is to shrink fat cells, we need to get the lipids out of the fat cells, which will in turn reduce the size of the fat cells. Insulin is the switch that determines fat burning or storing: it is impossible to burn fat when insulin is high and it is impossible to gain fat when insulin is low.
Dry Jason Fung makes the case for using intermittent fasting as means burning fat. The idea is to first consume the body's glycogen which then reduces the insulin level. Since insulin and glycogen are low, the body will then start converting triglycerides in the fat cells back into ketones and glucose. This requires you to fast (ie, not eat), which can be problematic for diabetics whose blood sugar can fall too low. Dr Fung suggests that there are benefits to alternate day fasting where cut your food intake on the fasting day to 500 calories. He regularly has 23 hour fasts - that is, he only eats once a day at supper. It appears that it is not beneficial to continuously graze all day but instead to allow your blood sugar levels to fall between meals so as to draw upon your glycogen stores. Especially if you're diabetic, make sure that you only undertake fasting with the supervisor of your doctor.
Similarly, it would be useful to engage in physical activities that also increase your caloric consumption. The body tends to use a greater percentage of fat with lower levels of endurance exercise intensity and the shift toward carbohydrate consumption increases with exercise intensity. Training tends to increase the body's fat metabolism which in turn improves the body's ability to conserve carbohydrates (carbohydrate sparing). Low to moderate intensity endurance exercise doesn't require your body to first draw down its glycogen stores. While low-intensity exercise favours fat metabolism, blood glucose is still impacted and the effect also temporarily increases insulin sensitivity after exercise. However, with training, your body becomes more efficient with glycogen storage so increasing amounts of physical activity could require increasing time for glycogen depletion.
Exercise opens another pathway in the cell to allow glucose. Increased physical activity causes an improvement in metabolic health by increasing insulin sensitivity while a sedentary lifestyle causes insulin resistance.
Cities often have Active Transportation programs (like Fort Erie's FEAT Committee) to encourage healthy lifestyles. Take advantage of your town's recreational trails and bike routes whenever you can but, with North America's car-oriented suburban environments, walking and cycling for errands may often be impractical. In parking lots, parking far from the entrance has the added benefit of reducing door dings and other parking lot mishaps. Take the stairs whenever you can.
Strength training tends to increase muscle mass and and additional muscle tissue increases the body's basal metabolic rate. Additional benefits of strength training include increased bone mineral density and increased connective tissue strength.
- Fat cell number is set in childhood and stays constant in adulthood | National Geographic
- Dr. Jason Fung - 'Therapeutic Fasting - Solving the Two-Compartment Problem'
- Depletion of muscle and liver glycogen during exercise. Protective effect of training.
- 5. Carbohydrate Metabolism During Exercise | Science of Exercise | University of Colorado Boulder
- 6. Carbohydrate Metabolism Continued | Science of Exercise | University of Colorado Boulder
- 7. Fat Metabolism During Exercise | Science of Exercise | University of Colorado Boulder
- Physical activity and its influence on obesity, insulin resistance and diabetes - Part lll, by Professor Bente Stallknecht
- Physical Inactivity Rapidly Induces Insulin Resistance and Microvascular Dysfunction in Healthy Volunteers
- The effect of exercise-intensity on skeletal muscle stress kinase and insulin protein signaling