High and low carb diets equally effective...as long as someone else is in charge
We've been talking a lot on the blog lately about quality vs. quantity of calories. On one end of the spectrum are those who insist that weight loss (or gain) is simply a matter of quantity: It doesn't matter whether you eat protein, fat, complex carbs, or sugar; if you simply eat fewer calories than you burn, you will lose weight.
On the other end are those who believe that quality is the key: you can eat as many calories as you want without gaining weight as long as they are the right kind of calories (i.e. protein and fat rather than refined carbohydrates).
Those in the second camp spend a lot of time talking about how refined carbohydrates stimulate insulin release which promotes fat storage, while protein increases thermogenesis and fat-burning. But I think the magnitude of these metabolic effects is greatly over-stated.
I suspect that the real "magic" of the low-refined-carb diet is that it tends to regulate calorie intake.
Refined carbohydrates tend to stimulate appetite and lead to over-consumption. But what if you take appetite out of the equation. What happens when someone else decides what and how much you eat? Consider this recent study:
After losing an average of 36 pounds on a weight loss program, obese subjects were put on one of two weight maintenance regimens: one was high protein and the other high in carbs. A year later, both groups were equally successful in maintaining their weight loss. The researchers concluded that "the protein or carbohydrate content of the diet has no effect on successful weight-loss maintenance."
When calories and macronutrients are "tightly controlled," the metabolic magic of the low-carb diet is undetectable. This would seem to support my suspicion: The primary advantage of the low-refined-carb diet is not that it recalibrates the body's metabolism and tendency to store or burn fat, but that it reins in appetite, thereby reducing calorie intake. Nothing wrong with that!
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Posted by: Gareth | Nov 18, 2009 2:29:32 PM
weight loss! what about fat % ; i am sure weight loss to a certain extent removes fat but I am also sure tight control of macronutrients helps with body fat percentage control.
Posted by: Brian | Nov 17, 2009 8:25:30 PM
I would like to see this study done with a bigger variation in the amount of carbs being used and also to compare lean tissue body composition. Not just weight, since weight can be a very iffy indication of health.
Posted by: Marie Hughes | Nov 16, 2009 10:26:58 PM
I find the best way to keep weight off is to count calories religiously. If you over eat you will put on weight. Watch content of alcohol.
Marie Hughes
Posted by: Louis | Nov 16, 2009 7:29:04 PM
When I was diagnosed as a Type II diabetic, I started a chart and monitored everything I ate, portions, protein, carbs, fat, etc and also kept daily measurements of my blood sugar, blood pressure and weight.
After 5 years of maintaining my chart and also giving copies to my doctors as necessary, I can predict, how my blood sugar, blood pressure and weight are affected daily, based on the food I eat.
I also tested foods in my body for their glycemic index. I found all the charts and tables available on the internet, never predicted the results accurately for my body.
I repeated the test for the period from Jan, 08 through Jun, 09. I was forced onto drugs to meet the blood sugar and pressure requirements to have an operation dictated by an automobile accident. My past experience proved to be accurate in this period of testing as well. In 6 months I was able to meet the requirement for the operation.
I now believe I can predict my blood sugar, blood pressure and weight simply by recording the food I eat and measuring it against the historic data. the result is almost always constant.
I know that the total calorie count and not the class of protein, carb, fats or portions of each, is what will determine what I will weigh tomorrow. I can eat anything I want, but, I have to manage the total calories.
I also know, what I have found for myself for example is not consistent for everyone else. It is more consistent between my wife and I than another person whom I charted.
I think the distinction is based on the fact that your body, individually, is based on what you eat and have eaten. My wife and I consumed very similar diets and we can predict change more consistently because we have done so for over 30 years.
I believe the reason diets don't work as a rule, and there are thousands of them, is because each individual body is extremely individual based on what it is built on. If a diet of any kind always worked, it would be the only diet. Each individual has to take the time to make their own determinations about their own body and set their own rules to follow to reach personal goals.
So, I suggest, for those of you who are serious about your own body, you start charting, accurately and completely what you are putting in your body. Keep your blood sugar, pressure and weight daily, and you will find your rules for your body. You can then practice those rules to guide you through the rest of your life.
If it is true you change every cell in your body every 7 years, which I am not sure how you measure, You should be able to build the body you want over some period of time.
Posted by: Icarus | Nov 16, 2009 4:23:14 PM
"In that study, the macronutrient (protein/fat/carb) percentages were approximately 30/30/40 and 15/30/55."
Ah, that would explain things. Researchers have a suspicious tendency to vary diet tendency only slightly, and then claim that macronutrient composition doesn't matter. 40% of calories as carbohydrate is hardly low-carb - on a 2000 kCal/day diet that's 800 calories or 200 grams of carbohydrate. 200 grams? Any low-carb diet worth its salt will max out carbs at about 120-130 grams, at most, or more like 10-25% of calories as carbohydrate.
"Both groups were instructed to keep fat intake to less than 30% of calories."
Well, there you go. It's not much of a low-carb diet if fat was restricted - you can't get much energy from protein, so the rest of your calories have to come, primarily, from fat, which is after all a great energy source. (Hence why it's your body's favored energy for storage.)
Posted by: Dave | Nov 6, 2009 9:31:40 AM
I'll bet you can explain this effect by looking at diet's effect on insulin, rather than just carbs etc. A low-fat low-calorie diet will reduce insulin as well, particularly if it is focused on whole foods, which tend to be lower glycemic.
Posted by: Abalone | Nov 4, 2009 6:54:40 AM
Thank you for digging out the details of the macronutrient composition.
Given that fat was held constant and carbs didn't vary by all that much, I don't think the study implies anything about low-carb diets, which are lower in carbs and much higher in fat. Best I can get my head around the alleged metabolic impetus of low-carb diets, it seems that much of the claimed benefit is supposed to be in the extra fat consumption. Still, the study is useful on the issue of the quality of reported vs actual calories consumed by participants in studies.
Posted by: Monica Reinagel | Nov 3, 2009 11:39:37 AM
@Steve Parker:
There was a large drop-out rate (probably due to the length of the study) but interestingly, about both groups had about the same percentage of drop outs.
Posted by: Monica Reinagel | Nov 3, 2009 11:36:53 AM
@abalone. A good point: diets characterized by investigators as "high" or "low" in protein or carbs are often pretty midline.
In this particular study, the high protein group was instructed to eat 30% of calories as protein vs. 15% in the other group. Both groups were instructed to keep fat intake to less than 30% of calories.
Both groups were also instructed to select low glycemic carbohydrates.
Posted by: Marg | Nov 3, 2009 10:57:13 AM
In that study, the macronutrient (protein/fat/carb) percentages were approximately 30/30/40 and 15/30/55.
Posted by: Abalone | Nov 3, 2009 7:17:54 AM
HP and HC can mean very different percentages from study to study. You can't tell from the abstract of this study the percentage of carbs and protein in the competing diets. We've seen studies before that compared high and low carb, for example, when the difference was trivial and the low carb wasn't low at all. This conclusion, if valid, is too important to accept without knowing the extent of the difference between the diets.
Posted by: Ali Dimayev | Nov 3, 2009 4:36:01 AM
Raw food diet?
No one is completely healthy on a raw food diet. Half of the women on it can't hold a pregnancy, for one.
Posted by: Steve Parker, M.D. | Nov 2, 2009 8:17:50 PM
Regarding the study Monica referenced:
Average weight loss over three months was 36 lb, no difference between groups. (2.7 pounds per week.) Over the next 12 months, average weight regain was only 5 pounds.
These are astounding results, much better than seen in real-world situations.
Why were the result so good? Probably because 52% of the original study participants dropped out before completing the 15-month study. I'm guessing their data were ignored.
[Confession: I don't have the full study, just the abstract.]
I remember reading one study indicating that successful very low-carb diets, on average, do reduce caloric intake below baseline levels. To about 1750 cals/day, if memory serves me well.
As you write, Monica: Nothing wrong with that!
-Steve
Posted by: TTC | Nov 2, 2009 5:13:36 PM
I've said it before, and I'll say it again: I've been eating a 75% carb diet for 2 years now. My BMI is 19.
Before, on a more "balanced" diet (i.e. less carbs and more protein/fat, but roughly the same number of calories overall), my BMI would fluctuate between 22 and 24. I'm happy for those who have lost weight by increasing their fat and protein intake, but I refuse to believe that it's the one diet that works for everybody.
Posted by: Elizabeth | Nov 2, 2009 4:56:32 PM
Paul and Steve, that approach may work for you/the people in the study. But everyone is different: some people are their healthiest on a raw diet, others on a paleo diet. I believe the only advice that these diet promoters should be spewing is: more fruits and vegetables, free-range/pastured meat, and unrefined carbs.
Posted by: Paul Bowers | Nov 2, 2009 4:47:34 PM
nothing about a human study is "tightly controlled". the metabolic magic (metabolic advantage) of low-carb diets has been documented. please read: http://ajpendo.physiology.org/cgi/content/full/292/6/E1724
Monica's Response: I'm not denying a metabolic effect, I'm questioning the magnitude of the effect (in humans).
Posted by: Steve Estelle | Nov 2, 2009 4:31:22 PM
I tried a high fat/low carb diet for several months (fat about 70% of calories with saturated fat composing the majority of fat calories). After a week or so, the hunger feeling changed dramatically. It was much less intense, more of a hunger nudge. I did not get that sick hunger feeling I sometimes get when eating a normal (33/33/33) diet. Nor did I feel the urge to snack.
