Usually, the first thing people do when trying to lose weight is to eat less. They cut back on calories. This reduction in energy should then result in weight loss. Makes sense, right?
Fewer calories in = Weight Loss
The energy in and energy out equation does make sense, but unfortunately there are other factors which complicate matters a bit more than that. Our bodies do not function like a math equation, not at all. Body Composition or how much lean mass vs fatty mass we carry is one of the things which plays a big role.
Most people can lose weight, at least for a short time. But what exactly are they actually losing?
Let’s take a look at what happens inside your body when you do cut back on calories and your bodyis adapting to that change. You are no longer getting quite enough energy to fuel your daily activities from food. You need energy for your brain to function, to digest food, to keep your organs working and to fuel the movements your body makes, even if you’re just walking or sitting. Our bodies are amazing at surviving and they will find a way to keep the body fuelled. The body will take the energy it needs from the its internal energy stores: muscle, fat, bone and water.
The body’s tissues burn different amounts of energy on a daily basis. Our lean mass (muscle) burns energy constantly. That’s because all the mitochondria, the little energy-making factories (remember high school chemistry?) live in the muscle tissues. This constant energy burn is useful as it aids in weight loss. Each extra kg of muscle you have increases the number of mitochondria and the hourly rate of energy that is used.
Fatty tissue burns very little energy. Let’s say we have two people who weigh the same amount. But one person is a gymnast and the other is an office worker. The gymnast has more lean muscle, a lot more. Let’s say they are both trying to lose a bit of weight. The gymnast will have a huge advantage as he burns more calories per kg of lean muscle mass, day in day out, 24 hours a day, even when sleeping. The office worker doesn’t have that extra lean mass burning energy constantly, so they will have to cut back MORE on calories to lose weight.
Two of the main sources of internal energy stores are the fat our bodies hold and the muscle we have. If not exercising, and not getting enough calories from food, the body will find about half of its energy requirements from muscle and half from our fatty stores. For example, when someone loses 20 kgs, about 10 kgs of that will be from fat and 10 kgs from muscle.
That 50/50 ratio of fat to muscle loss can be changed with exercise. If you exercise while trying to lose weight, your muscle loss will be minimised. This is important, as it will allow your body to continue to function as an efficient energy burning machine well into the future. However, if you are not exercising, the more muscle you lose over time, the less energy your body burns daily and the less calories in it needs. Starting to become clear now?
The more muscle you have, the more energy your body burns.
The less muscle you have, the less energy your body burns.
Dieting Over the Long Term
Yes, you can lose weight just by cutting back on your intake, but will it really be the result you are looking for?
Each time you lose weight if you are not exercising, your body will lose some muscle mass.
The faster you lose the weight, the more muscle you will lose.
And worse still is that if you put that weight back on after the diet is “finished” or your weight loss goal achieved, you will probably not gain the muscle you’ve lost. You’ll have gained more fat and lost some muscle. With this smaller amount of muscle your body will then burn fewer calories each hour on the hour.
The next time you want to try to lose some weight, you will have to eat even less. This is what is happening when our metabolism slows down and weight loss seems a struggle.
Sustainable Weight Loss
For sustainable weight loss, the focus should be on a healthy body, healthy mindset and delicious whole foods.
Here are a few tips to ensure you avoid muscle loss during weight loss:
- Exercise and ensure you prioritise resistance training as opposed to long cardio sessions to build muscle.
- Focus on small changes to the way you eat and on whole foods that nourish your body.
- Eat mindfully and slowly.
- Cook and prepare as much of the food you eat as you can.
- Eat as much as you can while still losing weight so that you don’t lose weight too fast.
- Keep lean protein intake high, about 20-30% of your total calorie intake.
- Think of the changes you make as lifestyle changes, not a temporary fix.