Fat loss is the result of a negative fat balance in your fat cells. Fat moves in and out of those cells depending on your body's energy requirement. Before we dive into the details, let's get a few points out of the way.
We have a fixed amount of fat cells in our body. We don't create new ones, and we don't burn fat cells to the point of extinction.
We lose fat cells due to cell death but our body generate new cells leading a fixed amount of fat cells over time.
You fat cells can get bigger or smaller depending on how much fat gets stored in them.
If we want to lose fat we need to have more fat leaving the cell than entering the cell
The food you eat influences how much fat your fat cells absorb and release
Your exercise routine influences how much fat leaves your cell
How fat gets in and out of the cell
Fat can enter your cells by two mechanisms: Lipogenesis and Re-esterification.
Lipogenesis is the conversion of glucose into fat. Glucose comes from carbohydrates that you eat.
Re-esterification (RE) is the absorption of fats that are in your blood stream. This can come from the fats you eat, or fats that have been released by fat cells
The only way fat will leave the cell is through a process called lipolysis. Your body increases lipolysis when it needs energy. This could be for exercise but will mainly be triggered by your non exercise activity thermogenesis (NEAT). NEAT refers to any energy demands that is not related to exercising, sleeping or eating.
When the rate of lipogenesis and RE is greater than the rate of lipolysis, your fat cells get bigger. When the rate of lipolysis is greater than the rate of lipogenesis and RE, the cells get smaller and you are effectively losing fat.
How to lose fat
There are many ways you can have a greater rate of lipolysis. You can achieve this by eating carbs, or if you prefer to eat more fats you can, you can exercise a lot, or just enough. You can do almost an infinite amount of combination of diet and exercise as long as the rate of lipolysis is greater than the rate of lipogenesis and RE.
NEAT and your exercise routine are the two main factors your can control to increase lipolysis. You body needs fat for energy during any exercise bout that is longer than 3 minutes with a relatively low intensity (less than 50% of your VO2max)
It is as simple as going for a short walk. Making this a daily routine can help your body tap into it's fat stores and if done consistently, rain or shine, will help keep your lipolysis rate going.
Low intensity exercise includes walking, cycling, hiking, swimming, jogging, rowing, going on the elliptical. The intensity of the exercise should be easy enough for you to hold a conversation the whole time you're doing it.
The other way you can increase your lipolysis is to increase your NEAT, which can be done by doing the following:
- Walking as much as you can. If you are using your car to get somewhere, park it a few blocks away from your destination, and walk the last few blocks.
- Stand more. Get a standing desk if you can. When watching TV, stand up for certain scenes or segment. If you're watching a TV program stand up during the commercials.
- Cook your meals. This is just another way to stand more.
- Take different routes to work or to your grocery store.
- There are an infinite amount of ways you can increase your NEAT depending on your lifestyle, if you need more ideas you can email me and I'll be happy to chat about it with you
Controlling lipogenesis and re-esterification
Controlling these two factors boils down to what you eat. I've written a few articles about this in these articles:
Eating more carbs or more fat does not make a huge difference in the total fat balance. If you eat more fat, like in a keto diet, you are going to reduce lipogenesis and increase RE, which will end up with the same amount of fat in your cells in a calorie equated diet. On the other hand, if you eat less fat and more carbs, you're decreasing RE but increasing lipogenesis.
Will building muscle help with weight loss?
One pound of muscle burns around 7 calories per day. If someone has 60 pounds of muscle, that means they will burn 60 x 7 = 420 calories per day just to maintain that muscle mass.
A strength routine aimed at increasing your lean muscle mass will help you burn more calories throughout each day to maintain your muscle mass.
The strength workout themselves won't burn a ton of calories while you're doing them, but the result will be more muscle mass.
What about cardio?
Cardio on the other burns more calories when you're doing it but does not build new muscle. It also helps enhance your cardiovascular system which indirectly helps your strength routine by enabling you to recover faster in between workouts.
For example, a 150 pound person biking at a moderate speed for 30 minutes will burn around 300 calories. The same person doing a weight training workout for 30 minutes will burn between 90 - 200 calories.
What is the best way to lose fat?
A balanced plan that includes strength training as well as cardio is in my opinion the best way to lose fat. You will be using the benefits of each workout together to maximize your results.
Having a nutrition plan that allows you to be in a calorie deficit most of the time should go hand in hand with the above exercise routine. To make sure the nutrition plan works long term make sure it incorporates food you love to eat, has contingency plans for going out, has enough fruits and vegetables and enough protein.
Fat loss is a result of your energy requirement which is influenced by your exercise routine (energy output) and diet (energy input). There are a lot of combinations that will help you lose fat, take the time to find one that is sustainable for you and that you enjoy doing.