#2: Carefully Controlled Calorie Intake
The first law of thermodynamics is an expression of the principle of conservation of energy. It states that energy can be transformed (changed from one form to another), but cannot be created or destroyed.
Our bodies take in energy (food) to perform work (measured in joules or converted to calories spent).
- stored as energy
- lost as heat
- used to fuel or support metabolic reactions
- used to fuel digestion
- not completely digested
Does this mean that for some reason the first law is being broken? That the energy going in is out of balance with the energy coming out?
No. What it means is that YOUR BODY IS NOT A CLOSED SYSTEM, and it RESPONDS AND ADAPTS to its environment and the stresses placed on it.
A VERY IMPORTANT LESSON:
"Fat burning" and "increased metabolism" are somewhat opposing terms. I know you've heard ads for products that claim to "stoke your metabolic fire" so you can "burn off fat". My advice: don't waste your money. Here's why:
- Losing fat (and by consequence, bodymass), effectively decreases your metabolism and increases hunger cues
Your bodymass directly influences your resting metabolic rate. The more mass you have, the more calories your body needs to function. When you lose weight, your requirement for calories decreases. The other side of this coin is that the higher the proportion of muscle mass to fat mass you have, the higher your metabolism. What does this tell us?
Any weight-loss program that fails to include progressive weight-training is destined to fail long-term by not attempting to combat the reduction in metabolism due to reduction in body-mass (other social strategies and meal planning options are necessary to combat this as well). Weight-training places necessary demand on the muscles to grow, or at least maintain mass. One of the most crucial elements of exercise physiology that goes ignored by endurance athletes who rely solely on endurance exercise to manage their weight is that the aerobic energy system actually uses 3 fuel sources (simplified):
- Fatty Acids (low intensity or rest)
- Glycogen/Glucose (higher intensity)
- Protein from deaminated muscle tissue (low or high intensity, amplified in the absence of stored carbohydrate)
Aerobics oxidize fat, but they also eat up muscle tissue. This is generally not an issue if you eat a moderate to "high" protein diet, along with refraining from training in fasted states (glycogen depleted), and if you incorporate progressive resistance training at sufficient intensities to stimulate muscle protein synthesis (MPS). Unfortunately, many endurance athletes I know rarely meet their minimum protein requirements, let alone that needed for athletes (1.2-1.8 g/kg bw/day). Their A) calories are often too low and B) carb intake to high to justify the a) distances they cover and b) how low their average intensity is. But that's a story for another time.
Bottom-line: the "fat-burning zone" is meaningless if you are overeating calories. If your goal is to lose weight you must create a caloric deficit by consuming less calories than your body needed that day. You can do this by eating less, or exercising more, or both.
What you DON'T want to do is train more and more and more while eating less and less and less. This is one form of what I call "spinning your wheels". It's kind of the parallel equivalent of training all the time but eating whatever you want - both result in running yourself into the ground and getting nowhere fast. Doing the former will provoke your body to adapt by lowering metabolism to deal with the excess work performed in the absence of adequate energy - a survival mechanism.
Support your body, don't starve it.
"Energy Rules! Energy Conversion and the Laws of Thermodynamics - More About the First and Second Laws". Uwsp.edu. Retrieved 2010-09-12.
Klok, M. D., Jakobsdottir, S. and Drent, M. L. (2007), The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review. Obesity Reviews, 8: 21–34. doi:10.1111/j.1467-789X.2006.00270.x
Antonio, J., Lowery, L. M. (2012) Dietary Protein and Resistance Exercise. CRC Press, Taylor & Francis Group. 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL
Nesheim, M., Nestle, M., (2012) Why Calories Count: From Science To Politics. University of California Press Ltd. Berkeley and Los Angeles, California.