In my previous articles I based my recommendations on my own kind, the tall and big guy category, however if you are a shorter, smaller person with a much lower BMR (basal metabolic rate) to start with, then I have a few additions or amendments to make.
On the nutrition course I took, the teachers pointed out that metabolism is an important part, which we want to keep working, even try to speed it up, because if our body is working more on producing energy from fat, then we will be losing fat faster, while on the other hand if we slow it down, then fat loss will be slowed down as well.
The diagram shows the BMR for the specific sex, age, height. The rectangle markings are showing the +60 kg to -20 kg range of height-100. I only included the same age and one height for comparison, height is not a big factor here and age similarly changes for both.
Children
I have applied this same BMR formula for children, but it was not designed for them. As per my current knowledge, a young kid, 4-8 years old, should have 1000 kcal for a female and 1200 kcal for a male, while the adult formula goes under these values, as it doesn't incorporate factors like they have a higher resting heart rate as they are continuously growing. On the other hand there is the similarity with adults that male children require more calories, which is probably related to the fact that they have more muscles by design, even if it not quite trivial at such young age.
The next part applies to children too, cutting is not an option for a child, because that would affect growth, therefore they need to be more active during the day for fat loss.
Calories for cutting
In the Beginning your diet journey I wrote that you should be cutting your calories by 500 kcal or 20%, this works well when you have a BMR of 2500, but you must be careful if you only have 1000-1400 to begin with.
By rule of thumb you should never go below 1000 kcal/day. If your BMR is 1200, don't cut it by 500, nor by 20%, it's already so close to 1000 that you shouldn't cut it at all. You want to keep your metabolism up and even make it faster, so eating less is not an option for you. You can still aim for healthier food, lower calorie, higher volume. So what can you do? Move! You can aim at that 20% calorie deficit by burning it with movement, cardio and workout. If you do strength training you will gain muscle, which needs more calories, so you can even eat more, of course that gain won't be fast, like plus 1 calories a day if you are doing it right, probably even less in the long run, but it will also tone your body, you will look better.
Now what about fasting? you may ask. There are the calorie restriction variants with days with only 500 kcal of consumption. Good question. That's still an option for you, probably the once per week variant, so you don't mess with your metabolism for a longer period of time and still get the benefits of having that nice calorie deficit for the week in one go.
Weight loss per week
In the Progressing your diet journey I wrote that you should expect a weight loss of 0.5-1kg/week, well again, if you are a big guy, but you might be a small child, so that won't happen. Moving more, burning 100-200 kcal of the maintenance calories will give a slow rate of weight loss, around 0.1-0.2/week. It doesn't sound much, but usually time flies by, that's why habits and discipline rules our lives, you create the habit of moving, working out, you will be doing it for the rest of your life, you will get to your better physique in 6-12-24 months, then you still have decades to live with that better body, that you keep perfecting even more every year. No rush, it's the slowest marathon of all, keep doing it, results will come!
Temperature
Keep in mind that temperature can play a role in our calorie needs. Thermal stress requires more calories as our body tries to keep everything within range. The most common case is when we go to swim in a cold water swimming pool, even if we just sit in the water for some time, we will get hungry, because it requires energy to keep our body warm. Same goes for ice baths, going out without sufficient clothing in the winter, or too much in the summer or having a sauna - if you wouldn't like to move just include yourself in a cold or hot environment to use more calories. Except for children, it might be harmful, just keep them moving. ⚽️ 🏀 🎾
Dieting for women and children