The History of Burning Fat vs Storing Fat
Our body’s energy metabolism exists in one of two states: we store fat, or we burn fat. What causes the body to switch from one state to the other? We are not quite sure, but a handy analogy is to think about the seasons we evolved with. There is a cold season (winter) and a warm season (summer). In winter, food is scarce and in summer, food, animal prey, is more plentiful. Plants also know that winter is coming on, and start to lay down stores, or make seeds. The energy storage medium for plants is in the form of carbohydrates (though nuts of course also contain oil), for animals and us, it’s fat. So, in spring, when animals come out of hibernation and feed on new shoots, their nutritional make-up is of protein and fat.
It, thus, makes sense that we as humans would also want to go into fat storage mode ahead of winter, and be in fat-burning mode next spring and summer. The obvious trigger for which state to be in would be the availability of the different types of food. Fat is more plentiful in spring and summer (and even autumn). Carbohydrate (in pre-agricultural times) was associated with the autumn (fall) season when the fruit ripened on trees and tubers swelled below ground.
Eternal Autumn (Fall)
Humans adapted to this natural rhythm of storing fat for the winter. With the prevalence of natural carbs in autumn (fall) we fattened up for winter. You see, Carbs trigger insulin secretion which promotes fat storage. During winter, with no Carbs available our bodies burn away the fat as nature intended.
Now, we are experiencing a Carb-rich Autumn 12 months of the year. Fruits are available the whole year, processed carbs are a part of our everyday diet. See the problem? Our bodies evolved to protect us against the natural cycle of the seasons. By mastering the art of agriculture, we have turned our bodies against us. We are storing fat for winter every day of our lives by eating Carbs. Restricting our carb intake is the only strategy to maintain a healthy metabolism. By restricting carbs we allow our bodies to burn fat – the fuel it prefers.
Burning Fat vs. Burning Carbs
Carbs and Fat can serve as sources of energy.
You’ll get carbs for energy from blood glucose, a simple sugar, or stored glycogen. Glycogen is a large carb molecule made of hundreds of glucose units arranged in branched chains.
Your muscles and liver keep a store of glycogen for almost-immediate energy. You start using glycogen for fuel as your muscles work hard — for example, during a workout. Your cells can also pull sugar from your bloodstream and convert it to usable energy.
You can get energy from fat as well. After you eat a fatty meal, fat gets broken down into fatty acids, which get absorbed into your bloodstream and can be used for energy. Stored fat — like your body fat ― also serves as a source of fuel. When you need more energy than you get from your food, your fat cells start to break down and release fatty acids, which your other tissues use. As your stored fat cells release more and more fat, they get smaller — so you’ll lose weight and look leaner.