There is a lot of hype in the fitness world about calories in versus calories out and eating less that you burn. Though this has some merit to some degree it is not as black and white as that statement appears. The human body is never black and white. In this article I will give you some science background so you can understand how many calories you require, then explain how 1,000 calorie diets don’t work, and how skipping meals, and starving yourself actually has the opposite effect of what you are trying to achieve.
Basal Metabolic Rate (BMR)
You see, your body has a certain number of calories that it requires in order for it to survive at rest. The best way I like to describe this to clients is, the number of calories you would require to survive if you were in a coma; no movement yet still requiring energy. This energy is called your Basal Metabolic Rate or BMR for short. This varies from person to person depending on their size, their muscle mass, their fat percentage, their gender, and their hydration.
To give you an example, a female weighing 60kg (without going into too much detail about all the other factors) requires roughly 1300 calories per day for her BMR. A male weighing around 80kg requires roughly 1900 calories.
Total Daily Energy Expenditure (TDEE)
You then need to take into account any movement the person does and add that to this figure. The more movement a person does the more calories they will require for their body to be able to function. You need to take into account the sort of job a person does, what general day to day movement they do, housework, gardening, walking, and any training. For example, someone who sits behind a desk all day won’t need as many calories as someone who is a nurse, on their feet all day. As a guide, a person requires another 40-70% extra calories on top of what their BMR is, depending on their daily activity. Adding this activity to the BMR gives you what is known as the Total Daily Energy Expenditure or TDEE for short.
If we add an extra say 50% for a not too active female (works in an office but then walks 5km every day and exercise for an hour each day), weighing 60kg, for example, she would require 1950 calories for her TDEE. The male in our example above, using similar activity as our female example, would require 2850 calories.
If they consumed this many calories they would simply maintain their current body weight. For them to drop weight, they would then need to go into what is known as a ‘deficit’.
Eating in Deficit
Once you have worked out your TDEE you can then decide to drop your calories by 10-30% so you can be in a deficit state, where you eat less than you burn. This percentage is the safest reduction to ensure your organs can continue to function with adequate energy, so you can drop weight, burn fat, burn muscle and not jeopardize your health.
Our female above at a 20% deficit would therefore require 1560 calories and our male above would require 2280 calories.
Looking at this, you can see how going on a 1,000-calorie diet can have long term effects on your health. It would be ok for a few weeks, but anything more than 3-4 weeks is firstly not sustainable, and secondly start to have serious effects on your health. The first sign would be fatigue and a drop in your libido. Stay with me as I explain in more detail.
Your body would initially think there is a short period of famine and tap into your stored fat stores for energy since stored fat is backup fuel for your body. Initially, you would feel amazing, burning fat and get excited and motivated that you are looking and feeling great.
However, after a few weeks, your body starts to worry that this is a long-term famine problem. As a result, it starts to slow your metabolism down to conserve fuel. So, you start to feel fatigued. It will start to reduce anything that is not vital for its survival so conserve fuel. The next thing that goes is your libido. If you do not have enough fuel for your organs to function, your body sure as hell isn’t going to let you burn vital fuel on sex, it isn’t vital for survival. It then starts to reduce sex hormone synthesis, as this too isn’t vital. You might find it difficult to form an erection or notice your menstrual cycle starts to play up.
On Comes the Extra Fat
When the body is hungry, breaking down fat as fuel takes a lot of effort, so rather than breaking down vital energy stores, the body will then turn to break down muscle tissue for fuel instead. So, you will find your muscle mass reducing despite your efforts in training, and your body fat stores going up.
Being in a hungered state, your body will be feeling very stressed and inflamed. Stress means an increase in Cortisol levels, your stress hormone. When you are stressed, your body is not burning fat; instead, it taps into your glycogen stores (sugar) in your cells. It releases the glucose into your bloodstream, thinking you need a quick burst of energy because you are in a fight or flight state.
If you are not burning this off, and you are just stressed, this glucose will not be burned off. So, your pancreas secretes insulin to remove the glucose from your blood and take it to the liver to convert back to glycogen for the cells. The cells have already been replenished of glucose in the meantime, so the liver converts the glucose to fat instead, and stores it as either visceral fat (the dangerous fat around your organs) or triglycerides, fatty acid, that it sends off into your blood as energy. Any triglycerides that are not burned off are then stored as adipose tissue, fat around your body. These triglycerides then increase your ‘bad’ cholesterol and increase the risk of heart disease. Your cholesterol elevates to try and combat the inflammation all of this is causing.
Skipping meals increases fat
If we combine all of the above and consider either the 1,000-calorie diet or skipping meals, you can see that the body is not getting enough fuel for it to survive and function in a healthy state. It will store as much fat as it possibly can, as backup fuel. So starving yourself is in fact making you fatter rather than helping you drop weight and fat.
Think about the starving population in a third world country. They are all skin and bones but with big bellies, not 6-packs! Their bodies are storing fat, back up fuel, in their bellies; visceral fat, the dangerous fat. This is what you are doing to yourself if you keep skipping meals!
Eating 4 to 5 meals per day, not snacks, in a 10-30% deficit, fresh food, keeps your metabolism ramped up, allows your body to trust you that it is not in a famine, and you will be building muscle and burning fat like a legend!
Meals are better than snacks as they keep you fuller for longer and give your body time to rest between digestion phases. It is not ideal to have your body constantly trying to digest; after all, it has other work to do besides digestion, such as burning fat and building muscle! Being fuller for longer also means you will not be overeating throughout the day. 4 to 5 meals also prevents binge eating.
Work out what energy your body needs, and fuel it like it is a million-dollar racing car! When you respect your body like you would respect a million-dollar racing car, it will perform for you and bring home that fat burning muscle building trophy!
- Coach Terri