The law of thermodynamics states that energy is not created nor destroyed, rather moved from one object to another.
Energy balance comes down to how many calories you consume through dietary intake vs how many calories you burn through fueling your lifestyle.
This balance dictates whether you lose weight, gain weight, or maintain weight.
“Calories in vs Calories out”
When it comes to calories in, your energy requirements are determined by how much oxygen you consume. For example, the oxygen needed to eat, digest, absorb, circulate, store, transfer energy, and burn energy.
When it comes to calories out, your energy requirements are determined by physical activity & movement, as well as the digestion, absorption, and transport of food. You have to take a deeper look into what’s going on in your cells. Positive & negative energy balance affects your metabolism, hormones, mood, etc. Constantly living in a negative energy balance can cause a host of issues. Symptoms include a decline in metabolism, performance, testosterone, and thyroid hormones.
“But I thought I had to be in a calorie deficit to lose weight?”
You do. You just can’t be too far into a calorie deficit and/or in a calorie deficit for too long, this is where issues arise…When your body doesn’t get enough energy, it begins to slow down or shut off “non-survival functions,” thus affecting the ‘calories out’ side of the equation.
On the other hand, if you constantly live in a calorie surplus then you will typically see weight gain, increased blood pressure & cholesterol, insulin resistance & diabetes, increased risk of certain cancers, etc.
‘Calories in’ is simply the dietary food taken into our body that gets absorbed/digested. These ‘calories in’ get converted into energy to power your muscles (work), can be given off as heat, or stored for later use. Work is any physical activity or exercise. Heat can be produced from the physical work mentioned above, the thermic effect of food, resting metabolism, as well as from adipose creation and thermoregulation. Energy can also be stored in adipose tissue and rates are dictated by the efficiency of work and food metabolism. As you can see, sometimes the equation is a little more complex than just calories in vs. calories out; your lifestyle and environment play such a huge part in this complicated equation. Your energy balance is regulated and monitored by an extremely complex network of systems.
This is why it’s so important to consider BOTH food quantity & quality. We will talk about this a lot more in the following sections.