June 30th, 2009
Low Carb Diets For Weight Loss: Just a Myth After All?
QUESTION: Tom, I’ve been reading your stuff for yearsand I also read a lot of other sites and message boardsincluding some of the low carb boards. I have finallycome to the conclusion, both from all my reading and mypersonal experience, that the idea that one will loseweight just by cutting carbs is a myth.
And I welcome anyone who thinks they can to go aheadand try to prove me wrong. I’m not looking for a fight of course, just looking for good information and discussion.
Consider the following two situations; each involves anidentical male who requires 3,000 calories/day to maintainhis current weight.
SITUATION #1: The individual reduces his calories to 2,500/day,which theoretically will result in losing one pound/week. Theindividual divides his calories so 60% (1500) come from Carbsand the remainder come from Fat and Protein. Will he loseweight even though he’s eating a lot of Carbs? I believethe answer is YES because even though the carbs are high (60%),he is in a calorie deficit.
SITUATION #2 The individual adopts a Low Carb Diet by eatingonly 25 grams of Carbs daily (100 calories). He then eats anadditional 2900 calories of Fat and Protein. Will he lose weight? I believe the answer is NO because even though the carbs are low,he is eating at his maintenance level.
Now, I understand that there are advantages to controllinginsulin and reducing Carbs, including some health benefitsfor some people, but what I often don’t see on the low carbbenefit list is the impact that fat has on controlling appetite.I believe that Fat satiates even the largest appetite, causingyou to eat less.
Therefore, I believe that the reason a Low Carb Diet worksis because people who follow it eat fewer calories.
I would love to get your feedback on this Tom and if you orany of your newsletter or blog readers have any studies orinformation proving me wrong, please let me know. -
- John in Texas
PS. I realize I’m not the first to question a Low Carbdiet, so my apologies if this has been discussed in yournewsletters or on your blog before.
ANSWER: Thanks for your well-thought out question John. Yes, we’vediscussed this before, but it’s timely and worth discussingagain, especially with some of the long-term research thatwas just published earlier this year.
You are preaching to the choir though, my friend. You areright, fat loss hinges on calories in versus calories out.
BUT — and there is a big BUT — we really need to make somedistinctions about low carb and high protein so we don’tthrow out the baby with the bathwater. Low carb has someadvantages. More imortantly, so does high protein.
Heres where most of the confusion comes from in this wholelow carb thing:
Are we talking about low carb in a free-living / ad-libitum(non calorie counting) situation, or are we talking about alaboratory-controlled study or a strict calorie-countingsituation?
This makes all the difference because in a real world (free-living) scenario, low carb almost always beats high carb for weight loss, especially in the early weeks and months onthe program.
This can be partly explained by water weight and glycogen loss in the intital weeks, but also by actual greater fat loss during the early stages.
However, this is not because of “metabolic advantage” of low carbs over high carbs, it is because subjects in these types of studies ate less in the low carb group.
In other words, low carb diets usually control calorie intake better, when you’re not counting calories (you get “automatic” calorie control, provided you’re not a totally unrestrained eater, of course).
So you are correct in your conclusion.
Furthermore, it’s difficult to eat too much when you removean entire group of calorie dense foods (sugars and starches)which are a food group responsible for providing a hugeportion of the calories in most people’s diets.
Sure, you can overeat on dietary fat as well, at leastin a mixed diet, but apparently not easily in the absenceof carbs.
Now, heres the kicker…
As soon as you start controlling calories.. I mean hospitalward or research facility controlled, where the subjectscannot pick and choose their own food, and instead, the foodis weighed and measured and almost literally spoon fed tothe subjects, the difference in weight loss between lowcarb and high carb shrinks or even vanishes.
In other words, when calories are matched, there is littleor no difference in fat loss between a high carb and low carbdiet, when dietary fats and carbs are the variables manipulated.
In the long term studies, even more valuable data has emerged…
The big study by the New England Journal of Medicine that got allthat publicity earlier this year confirmed it once again…
Even though low carb diets work better in the short term forweight loss in free living subjects, the advantage decreasesby month six, and disappears after a year or two.
The moral of the story is (drumroll please)…
Most people don’t stick with ANY type of diet very well for very long.
And… the extreme low carb diets in particular have lower longterm adherence rates and poor long term maintenance rates.
Now, this does not mean that low carb diets do not havebenefits. They certainly do, and some of them are healthrelated (which is beyond the scope of this column).
Other benefits are fat loss related…
If you automatically eat less due to appetite suppression andremoval of calorie dense foods, that is clearly an advantage,it’s just not the advantage that most low carb advocatessuggest.
There is no proof of metabolic advantage purely fromrestrction of carbs and insulin does not lead to obesityin a cause and effect sense, insulin merely plays a rolein the process of partioning surplus carbs into fat storesor in suppressing fat release.
Insulin is important to manage, but not the deciding factorin whether you lose fat or not.
One change in macronutrients that DOES help fat loss is anincrease in protein. Protein is highly thermogenic – about 30%.
So 30% of the energy in protein is not available for potentialfat storage, as it is metabolized just in the digestion process.
So in reality, you could say it’s the higher protein, NOTthe reduced carbs, that provides the real advantage!
Ironically, a low carb diet is NOT always high in protein! Ketogenic low carb diets for example, are actually high in dietary fat, not so much protein. most people don’t realize that. Too much protein is somewhat gluconeogenic and kicks people out of ketosis.
Likewise, a high protein diet is not always low in carbs.Take the 40-40-20 macro split from BFFM (or BFL) for example.40% of calories from protein is very high. And yet 40% carbsis not very low!
The protein-induced thermodynamic advantage is somewhat small,but it’s significant if a large shift in protein intake is madeas is the case with a 30-40% protein program.
For example, the old food pyramid/ traditional dietician-stylediet is 15% protein. Research from the University of WashingtonSchool of Medicine showed that when protein is doubled to 30%(replacing carbs), there is a small but measureable advantageeven when matched calorie for calorie.
In free living studies, the advantage is even larger becauseprotein is a great appetite suppressant and is highly satiating.
In fact, protein NOT FAT, is the most satiating nutrient.
It appears that fat is psychologically satiating, but proteinis the hands down winner as the most satiating, appetitesuppressing macronutrient, physiologically speaking.
Thus, a protein with every meal and a 30% (or even higher) ratio ofprotein is conducive to better fat loss – which incidentally isEXACTLY how the Burn The Fat, Feed The Muscle program is set up.
Theres much more to good nutrition and health than justcalories, but ultimately the most important factor is notmacro ratios or low carb vs high carb.
When you sort it all out, fat loss all comes down to acalorie deficit in the end.
In my 26 years of bodybuilding and 20 years as a fitnessprofessional, I’ve tried it ALL…
I’ve gotten ripped on high carb and I’ve gotten ripped onlow carb; thousands of others can testify the same foreither side.
What successful approaches have in common is a calorie deficit…AND they are programs you can actually stick with.
I simply believe that if you can get even a slight advantageby bumping up the protein and dropping the carbs, at leasta little, why not take it? So that’s why my bodybuilding-stylepre-contest maximum fat loss program is high in protein andlow to medium in carbs.
learn more at ====>www.BurnTheFat.com
Train hard and expect success,
Tom Venuto,
Fat loss coach
www.BurnTheFat.com
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