Very low calorie diets don’t work in the long run guys and there is a few reasons for this, namely homeostasis, the processes in which your body adjusts to keep a balance. That and the fact that it’s just not maintainable to live this way.
To avoid the trend of yo yo dieting where your weight fluctuates often and by large amount we need a more sustainable way of living.
When you restrict your calories for any long period of time your metabolism will start to slow, in the simplest explanation your metabolism is how freely your body uses energy. This continual slowing is often expressed as a sticking point in a diet, the point where you stop losing weight doing what you have previously been doing exercise and diet wise. To get past this point you will normally have to increase your caloric deficit by either eating less calories, exercising more or a combination of the two.
It’s almost a case of diminishing returns because the leaner you get and the few calories you eat the more your diet and body starts to work against you.
For example TEF thermic effect of food is the energy expended from digestion and transportation of the food we eat & it equates to around 10% of total energy expenditure. However as the amount of food you eat decreases so does the TEF leading to less energy used.
Also if you now weigh less it takes less energy to move your body so once again you are using less energy, add that to having less muscle mass and you start to see the bigger picture.
Once your body fat % is in single digits your hormonal output will start to suffer too. This lack of testosterone can be explained for why men often don’t wake up in the morning with an erection.
See when you greatly restrict calories in the short run you will lose weight, I say weight and not fat as many people when they reduce calories do it to the extremes & will inevitably lose muscle too. This is something we want to avoid as muscle is metabolically active meaning it uses energy, so the more muscle you have the more calories you can eat a day and still maintain your weight. This also makes dieting easier as you will be able to diet on a higher number of calories per day.
The simplest way to keep muscle while dieting is to diet slow and once you are below 12% body fat for men aim to lose 0.5 – 1% of total BW per week while keeping your protein levels adequate. This will ensure minimal muscle wastage.
Problems arise when you have a low calorie diet for a long time period, as you will most likely lose a substantial amount of muscle, you will also go through several sticking points meaning your calories will move progressively lower. All the while your metabolism is slowing and adjusting to your diet, ultimately stop you losing more fat.
This is why a diet must be a continual life style change and not a massive drop in calories for 6 weeks, sure sometimes your weight will increase and other times it will decrease but ideally not in excess on either side of the scales and not for prolonged periods. As too long with too little calories will create the above and too long with too many calories will create excess fat and it’s associated health risks. Also once you create a fat cell it will never go without surgery such as liposuction, this is why some people can find it easier to gain fat, bloat and retain water.
For those who have a lot of weight to lose or are trying to get very lean for a holiday, photoshoot or competition. Once your diet has been used for 8 weeks we’d advise a diet break where calories and often carbs are increased for a short period of time. This will increase your body weight and fat initially but it will also allow you to carry on and lose more fat in the long run, not to mention giving you a mental break from your cravings. Remember fat loss is not linear it will go up and down, expect that and adjust intelligently.
The diet break will stimulate your homeostatic environment and allow certain hormones to recover if you will. Namely leptin and ghrelin our hunger hormones, testosterone will have a short increase too but is expected to drop shortly after continuing the diet.
How the Yo Yo dieting starts
Let’s pretend we’ve been in a big caloric deficit (low calorie) diet for a long time and we have lost will power to carry on, either via not being happy with results or just bored of feeling tired. So you throw in the towel and go back to eating a higher calorie diet. Only this time you go back to your previous “normal” diet but with a slowed metabolism due to your previous long restriction in calories. So you are now consuming larger quantities of foods and thus calories but with a body that is reluctant to use energy in the manner it would have previous to dieting. Here is where you will possibly end up gaining much more fat than you lost, plus you have less muscle due to your previous restriction. So all in all not ideal!
If you are in the position of being on very low calorie diet and especially if you are still overweight i’d suggest you start to slowly increase your calories week by week. This way your body can adjust and your metabolism will start to increase hopefully without gaining lot’s of unnecessary fat. Then once you are back and well above your BMR you can decide wether to diet again, the idea is you gain little fat while increasing your calories slowly but you still speed up your metabolism allowing you to eat more, feel more normal and eventually start to diet again but in a safer manner. This may take several cycles before you reach your goal weight, but once there you should find it easier to maintain your goal weight due to eating more calories. It’s also important to use resistance training while building your calories back up and we want to re-build any lost muscle and more if we can.
Take away points
Diet sensibly & play the long game, you will fair better.
Use a diet break every 8 week or so to reset hormones and homeostatic environment
Understand that fat loss is not linear and some weeks you will not lose any fat despite a calorie deficit
The lower your body fat and the less your calorie intake is the harder it is to lose fat
Aim for 0.5-1% lose of bodyweight per week.
Keep protein levels elevated in order to preserve vital lean body mass
Save cardio until later in your diet when you hit sticking points
Thanks for reading, feel free to leave a comment or question.