Realities Of Dieting
There is an inherent truth in dieting that a lot of people forget. It’s one that seems to continue to appear time and time again, so instead of it being discussed privately I figured making a blog to explain it much more helpful to everyone.
When we diet from a high body fat percentage to a low body fat percentage there is a reduction in how much food can be eaten. Simply put, you eat less because you weigh less. A lot of people seem to think that when you finish dieting you can return to eating as much as you were before but forget that eating that way would in fact return you back to the body you had before.
Now I want to explain how and why in detail below so that you can grasp this concept a little easier, and I will do so with girls and guys as an example so that you can appreciate it closer to home.
For starters, your food intake is made up of the following;
Resting Metabolic Rate (RMR)
Your RMR is the cellular cost for your body to do things that are required of you everyday. These are things you don’t even consider but are not limited to; respiration, circulation and secretion. These must be at a true equilibrium to determine the Basal Metabolic Rate, but since that is harder and there is availability of context for the individual their RMR is the next best thing. You can calculate this using an array of formulas or direct measurements and fall within 10% accuracy.
Non-Exercise Activity Thermogenesis (NEAT)
NEAT is the thermogenesis that accompanies physical activities other than volitional exercise, such as the activities of daily living, fidgeting, spontaneous muscle contraction, and maintaining posture when not recumbent. So, think of this as things that cost energy but aren’t a part of formal training.
Thermic Effect of Food (TEF)
TEF, or Diet Induced Thermogenesis as some will know it as, is the increase of energy expenditure above basal fasting levels divided by the energy content of the food ingested. It really isn’t much and as an average is considered about 7 - 10% of the food you eat is lost to this. Proteins, carbohydrates, fats and alcohol all have a different range and in typical mixed meals which most people consume it is averaged out. It’s the smallest portion of your TDEE and least likely to have an impact.
Thermic Effect of Activity (TEA)
TEA is the energy that is expended during formal activity and can be a large portion of the TDEE. However, this is limited to the time availability for training, type of exercise and duration of intensity that alters this. For most people who don’t want or simply don’t have a large amount of time to dedicate to exercise this is typically limiting in their TDEE.
This all combines to create our Total Daily Energy Expenditure (TDEE).
Now let’s start to look at how the TDEE’s of different people can be impacted from dieting and what those numbers may look like to you.
So let’s make up someone. Sharon weighs in at 60kg, is 160cm tall and is 30 years old and wants to lose 10kgs of fat to achieve 50kgs of bodyweight. She also exercises 3-4 times a week at around 30 minutes per session. Little bit of weights or some circuit work. Maybe a bit of cardio.
Her BMR is approx. 1289 (1160 – 1417 +/-10%) kcals. This puts her about 1772 calories needed per day for her to maintain her weight as is. This has her eating at 29.5cals/kg of bodyweight or for our international friends 13.4cals/lbs. Now this relationship between bodyweight and food is important. Yes we know fat and muscle have an impact on the amount you can eat but it isn’t as much as you can assume (check out our IG page for that).
When Sharon finally achieves her goal weight loss of 50kgs her new BMR is 1189 calories per day and if she is still training as much as she was when she started, she can eat 1474 calories to have the same ratio of food as she was eating when she started.
That is a 298 calorie drop over however long in just eating the same amount of food that she started on. So nowhere close to her eating the same or more food at a lower bodyweight.
Let’s take a look at Darren. He is a 90kg guy, 179cm tall, 30 years old and wants to lose 10kgs as well. He trains the same as Sharon to keep all things similar here.
His BMR is 1874 calories a day and his training puts him at 2576 calories a day. This is a ratio of 28.6cals/kg or 13cals/lbs. His BMR is now about 1774 calories a day. Now when he is finished dieting down that 10kgs and hopefully hasn’t lost any muscle tissue and only fat mass he would be able to eat 2288 calories a day keeping that same ratio of food intake to bodyweight. 288 calorie loss.
Similar situation in both where a large number of calories are lost. Now as a percentage of food Sharon lost 16% of food intake through that 298 calories lost and Darren lost 11% of his food intake.
Now I know this isn’t fair, why does one person lose way more than the other. Well that comes down to bodyweight, height and sex (very tiny amount) differences. Body fat numbers may also change this as these were calculated off of very generic broad figures so yes someone who is losing more body fat than the other may experience less overall loss but it isn’t as much as most people hope.
So what can you do about it?
Well there are two things.
You can increase your formal training or find ways to increase your NEAT. Both will have an impact on your TDEE but the one that will provide the most is the one you can dedicate the most time to.
If you’re only about to walk an extra 30 minutes, intermittently spaced throughout your day, then you may get a small benefit in faster fat loss from that, but the calorie expenditure from it isn’t as high. Same if you’re able to do 10 minutes of HIIT, the intensity maybe high, but the down-regulation in your NEAT may be impacted through fatigue so it isn’t as simple as doing more hard work.
It is about finding a balance of things you can do that costs the most energy for the longest period of time. That my friends, is cardiovascular training. Weight training will offer the next best cost per minute but nothing can beat doing some cardiovascular training.
But no, that doesn’t mean now you have to go out and do some more cardiovascular training. You just have to find the most amount of activity that you are willing to do to eat more food. One thing to consider is that too much activity with not enough food can become a big impact on your recovery for your other training amounts. So again, find that balance.
In order of this priority; things you want to do to eat more, things you can do to eat more, things you can recover from and still eat more, things you’re not willing to do.
Diet Smart. Not Hard.