Actually hunger is just the signal to remind us that our body needs fuel in order to perform its duties. Our food serves to support our bodies homeostasis. Bu what is that? Well, food is fuel, without fuel we wouldn’t be able to create energy for our cells to work.
Pang et al describe this interaction nicely in their study on energy and metabolic homeostasis and human health.
“The energy substances (mainly carbohydrates and fats) are the basis and guarantee of life activity, especially the oxidative phosphorylation for energy supply.” 1
Our bodies usually do a great job of keeping our blood sugars in balance. Think of it in economics terms, if all other factors remain equal, when supply = demand we have equilibrium. And that for us humans means homeostasis. What we are talking about is the relationship between the availability of glucose and demand the body has for it. If you under or over supply then the bodies demand fluctuates, which our sensitive bodies don’t like.
Once you eat, your digestive enzymes fire up ready to break down your food so that you can use it for energy production to fuel your daily needs. And what’s that? Well its BMR, Basal Metabolic Rate, basic energy requirements to survive (~70% intake of daily consumption), exercise (~20%) and even digestion needs energy (~10%)2.
Take a breakfast of cereal, milk, coffee, maybe even a slice of toast and glass of juice. These foods are quickly broken down as glucose, as the blood sugar level rise, insulin is release beyond its required amount. Some glucose is used up by the cells, and the rest circulates in the blood system to be eventually stored as fat around the middle. And really irritatingly the sudden surge of insulin causes a blood sugar levels to drop so quickly that the body perceives an energy need again and so the cycle continues. This pattern of high energy and sharp drops to low energy is what we term the blood sugar rollercoaster.
Just like our supply/demand of products, if you are sending too much or too little food into your body, your body sugar levels sharply rise and fall creating unpalatable symptoms. Economically, your body will face an opportunity cost of eating the higher GI foods. These are the symptoms like:
– being hangry irritable mood
– even cravings for something sweet even though your tummy is full.
And it seems for many reasons beyond our conscious control, we continue to supply a much greater amount of these high GI foods than our body actually physically needs. What do I mean? WE all know that eating the food isn’t good for us but there are very strong physical and physchological urges dictating this behaviour.