Fundamental Macro Question

S

soflsun

New Member
I think is safe to assume that there needs to be a caloric deficit in order to drop body weight.  I'm also comfortable with the fact that by cycling calories it may be possible to stunt the metabolic slowdown inherent of dieting.

The big question still remains:  Is there a specific diet that allows the body to preserve lean mass better than another?

There is some debate on this topic, and I'd like to highlight THE MAJOR difference to see what you guys think.

Dietary FAT

While the prevailing diets seem to agree that limiting or eliminating carbs is good for fat loss, either due to insulin response they illicit or because depleting glycogen stores forces the body to resort to burning fat for energy, they disagree if dietary fat (other than Omega 3's) is beneficial or necessary for an optimal response.

Does the addition of dietary fat, although increasing overall calories, have a positive impact on p-ratio?

This can be seen in the CDK diet, where dietary fat and protein is kept high and carbs are kept to a minimum (except for a carb-up on the weekend.  Dietary fat is considered to be necessary for fat loss on this diet as well as a daily caloric deficit.

PSMF, for example, does not consider dietary fat necessary (other than Omega 3's).  In fact, the addition of dietary fat is considered to be detrimental to the loss of body fat.  This diet also has breaks or periods where you can carb-up.

This is a major difference in opinion in 2 diets than both apparently work.

Given the same daily caloric intake, will a diet with or without excessive dietary fat promote more body fat loss/lean tissue protection?
 
PSMF is not really a diet that can be used an example of diets in general. There isn't a more extreme diet that is still based on science and that is concerned with saving LBM.

To answer your question at the bottom of the post very simply, given the same calories, since high protein is the constant that doesn't change for people dieting to lose fat specifically and keep LBM, the diet with higher fat is better because after protein, you only have either fat or carbs to make up the difference.

For a more general diet, after protein, carbs should be kept around 100-150 (I wouldn't increase carbs more than 150 g unless you have a very good reason for it). Then, whatever you have left over in your calorie bank goes to fat. Have a carb load cheat meal or day once a week or so, and you are good for a general, long-term diet plan.
 
Cycling calories will stunt slow down but will also slow down the diet. Basically, refeeds or free meals are necessary to minimize hormonal shutdown. Despite addding energy back into the system they actually help goad the process along.

The ideal diet for LBM sparing would be something like this:
Protein up to a certain point (depends on weight, LBM, etc)
minimal calorie deficit
enough essential and nonessential fats to maintain optimal hormone production
chemical aid (bromocriptine, ECA, steroids, etc)
diet must be coupled with heavy lifting full body compound lifts 2x wk
enough carbs to optimize heavy lifting
high nutrient density foods (whole foods) to make sure nutrients are optimized
Proper and minimal refeeds/carbups and diet breaks to support optimal diet efficiency.

The bottom line for eliminating carbs for dieting is the fact that there is no such thing as an essential carb. To humans carbs are just energy. The point of a diet is to minimize energy intake so that the body uses its energy stores (preferably fat), so carbs are the first thing to minimize/eliminate. The body prefers carbs to fuel certain systems but it can do fine without.

You have to understand the spirit of the diets.

PSMF is designed to lose fat as quickly as possible for a very short time while maintaining LBM. To this end it eliminates all calories that are not necessary for hanging on to LBM for this short period of time. Protein, being the most protein sparing nutrient, is necessary but kept to the minimum necessary to reach the goal of LBM sparing. In the short term, non-essential dietary fats are not necessary and only contribute to energy intake. If you want a short intense diet that spare LBM, use Lyle's PSMF.

The other diets that contain fat are intended to be more long term sustainable diets. Fat must be increased to a minimum level (again dependant on many factors) to support optimal hormone production. These can be longer term even lifestyle diets because all essential nutrients are being acquired.

Comparing both diets using the same amount of calories ruins the main advantage of the PSMF. You can create a higher calorie deficit with PSMF and thus lose fat faster. Given short term ("short" depends on many factors) and compared isocalorically, the diets should perform similarly. Longer term isocalorically PSMF will hit a wall since you are not getting enough fats to support optimal hormone production in the long term, but again the PSMF is not intended for long term.
 
To answer your question, dietary fat will not do much difference in a diet, other than slow it down. If you ingest a lot, you'll get a small increase in fat oxidation but nowhere near as much as to compensate the input. What determines the fat burning rate is the total fat stores and the$ mix and storage of other nutrients (primarily carbs). Since gluconeogenesis (GNG) is the preferred way to supply glycogen critical tissues with fuel when whole body stores of glycogen gets depleted, the protein sparing way is to eat either protein (that gets used for GNG) or carbs. Dietary fat will only be stored (in muscle and adipose tissue), then it will be mobilized, if necessary, for use as fuel. Studies agree with the fact that it isn't protein sparing (neglible GNG contribution). Especially if you compare a high fat diet to other equicaloric diets, because, in order to keep the same calorie content, you need to remove twice as much carbs and proteins, which is a bad idea (at least the protein part).
 
Dont forget that fat (triglycerides) can be used for GNG via glycerol. Its not the preferred way to produce glycogen, but the body will do so when necessary, especially when its burning fat anyway (such as dieting or low carb).

Also, dont forget about the fat being the building block of hormones issue. In a short term diet the body has no problem using stores to maintain hormonal equilibrium although it is not optimal in terms of hormone synthesis. As the diet stretches longer and the body decides to hold on to fat better then this hormonal pathway is blunted. If no fat is consumed then hormonal profile begins to suffer even more and the protein sparing effects grind to a halt.
 
Some of those experimenting with PSMF have concluded that you need at least .7 gram of protein per pound of body weight in order to limit LBM loss.

I tend to go with Lyle's recommendations on such things. I wouldn't want to go less than 1.5 grams of protein per pound of body weight. Perhaps 2.0 grams would be even better.

Once you've got your protein right, you can play with fat and carbs as much as you like until you find a diet you can live with.
 
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