Food is fuel. Delicious, nutritious fuel.
As with any fuel, of course, some burn cleaner and some are better suited for different purposes. Natural gas, for example, has twice the energy content than coal (55.5 MJ/kg vs 26 MJ/kg) and produces half the CO2 when burned.
Why, then, do we still burn coal for electricity? Because it’s cheap and easy.
Sound familiar? If farms were located on every main road, had drive-thrus, and were as cheap as fast food, then maybe, just maybe, people would change their eating habits.
Food as a fuel source
Scientifically speaking, energy is measured in calories. Technically, this is the amount of energy required to warm one gram of water by one degree Celsius. What does that mean for food?
Food energy is measured in food Calories. For example, 1000 calories = 1 Calorie or 1 kcal. You’ve seen this information on labels, and in the last few years, on menus. The amount of Calories in an item of food is determined in a lab, where scientists light it on fire and determine how long and how hot it burns. This indicates the amount of total energy an item has. It does not take into account at all how your body digests and absorbs that food.
The average adult female burns in total around 1800-2200 Calories, and males burn slightly more – 2200-2800 per day. This figure varies widely based on your base metabolism, your age, genetics, set point weight, medication, gut bacteria… and the food you eat. One gram of fat contains approximately nine Calories, while a gram of carbohydrate or protein has about four.
The thing to remember is, calories are JUST a number. There are no evil ‘calorie molecules’ in your food.