Why you don't want to set your cal deficit too high

Silverkittycat: Theoretically, I think that could actually work. But put into practice is difficult. How do you know the exact cals required at your goal weight? You can estimate but everyone is different.

Monday, 06 June 2011 07:51 Rob Clarke

I assume all of you know of this story. Like the cat and the fox it is attributed to the philosopher Aesop. Different people seem to come to different meanings for the fable, but the most generally accepted is that “slow and steady wins the race.” This is the meaning I want to use for this article.

For anyone that has never heard the story, it goes along the lines of this. The hare is rapid and can cover great distances very quickly. The tortoise is slow and sluggish, which the hare one day mocks, thus explaining how some people identify the story as being one of arrogance and comeuppance. Amazingly, in retort the tortoise challenges the hare to a race! While this is an act of arrogance in itself, many people use it to illustrate that confidence and goal-setting is vital to reaching your goals.

During the race, the hare sets off at speed, reaching such a commanding lead that he decides to have a nap mid-way through. He awakes to find that the tortoise has been trundling through the race non-stop during the sleep and has just reached the finish line before him. Thus, slow and steady wins the race.

The relevance in this story comes from the notion often cited in bodybuilding circles that dieting down takes time and patience. If you try to diet down too fast you will inevitably lose muscle (the body can only burn through so much fat at any one time), not to mention the mental aspect of wanting to be in shape within a week. Many people find it massively disheartening when the changes are slow. Because of this they tend to do stupid things like cutting calories even further, starving themselves or doing huge volumes of cardio. This was the primary topic of the article I wrote about the blind force of the sub-cortex. Instead you need to mentally prepare yourself to drive through your diet consistently over time, constantly gaining ground at a steady speed. Not everyone wants to hear this, but I’d afraid it is the best way.

In fact, it has recently been investigated by researchers in Oslo and published in the April issue of the International Journal of Sport Nutrition and Exercise Metabolism. The authors of the study acknowledge that when it comes to making weight, athletes are recommended to lose between 0.5-1 kg (~1-2lbs) per week. They wanted to see if it made more sense from a strength and muscle retention point of view whether the aim should be 0.5kg/week or 1kg/week. While the swing of 1lb per week doesn’t sound like much, the study used elite athletes where small margins can make huge differences.

The use of elite athletes in this trial may have slightly confounded the results as many of the twenty-four that participated in the study competed in competitions not long after the trial ended. Therefore they had to begin their preparation during the trial, so the training routines between participants could not be standardized.

The participants were split into those aiming to lose weight slowly (a bodyweight loss of 0.7%) that reduced their calorie intake by about 20%, and those aiming to lose weight quickly (a bodyweight loss of 1.4%) that reduced their calorie intake by about 30%. This is where the issue of having elite athletes prior to competition comes in as the length of time the participants spent on their program was not fixed. On average, those in the slow weight loss group spent about eight-and-a-half weeks on the diet, while those in the fast weight loss group only managed just over five weeks. So the slow loss group spent around three weeks more strength training than the fast loss group. Bear that in mind when you see the results.

Both groups lost pretty much the same total weight (around 8-9lbs), but the slow loss group had a higher amount of their weight lost as fat (around 11lbs of fat was lost in the slow group versus the 7lbs lost in the fast group). The slow loss group also had a small increase in lean body mass (around 2-3lbs) whereas the fast loss group didn’t appear to add any.

As far as the strength and power retention during these interventions, they measured differences in the bench press, forty-meter sprint and vertical jump. The only real positive difference (indeed any difference) noticed in these measurements was in the bench press, and this was only in the slow loss group. This may be explained due to the longer time spent in the program by the slow fat loss group – the more they spent adapting to the stimulus the better they can become at it.

So despite the study not being great in it’s design, it does reinforce something seen time and time again in the real world. That is that trying to lose weight too fast ultimately results in loss of muscle and loss of strength/performance. Rather than being impatient and expecting to see results within a week, prepare yourself for the marathon of fat loss and muscle retention/gain. The hare expected to win the race easily and look how that worked out for him.

hmmm.....I still don't understand why you just can't eat the calorie amount for the weight you'd like to be. Won't you get there eventually? I'll go read the article now. :blushing:

The issue is muscle mass, you need a certain amount of calories to maintain that muscle mass. A big part is also protein ratios. I calculated how many calories mine and chrisdaveys muscle burns per pound. I think it was like 12cal/day/lbs. Our fat burns about 2cal/day/lbs. Just with these numbers you can see muscle mass burns a lot more calories than fat does.

If you lower your calories too low, you do risk losing muscle mass which will greatly lower your metabolic rate, which means to get more results you have to exercise more than normal or eat less than normal which just leads in to a never ending spiral.

Is anybody able to access the full article? I was curious to know whether they measured 'lean body mass' or 'lean tissue mass' as it would make quite a difference to the implication of muscle being 'gained' as increased/preserved bone density from exercise and proper nutrition could also be a factor if 'lean body mass' was the measure used.

Just had a look at the study a bit more.

"elite" athleates may be a bit over the top.

countermovement jump 32cm
40m sprint 5.8seconds
1rm bench 59-73kg
1rm pull (deadlift or row?) 63-69kg
1rm squat 90-97kg

Unless this test was only done on females that is

WIll go through it more a bit later.