Reader's Digest Smears Low-Carb

matthew's picture

I encountered this poorly-researched, inaccurate, wildly deceptive smear piece against low-carb eating this morning, and had to respond.

Just read all the posts by people who believe that dietary fat is "easily converted to body fat", like this guy: I'm profoundly disturbed by quotes like this from people who, despite their impressive results, don't know what they're talking about:

Fats and oils are the worst nutrients for people who want to lose body fat. They contain the highest amount of calories (9) per gram, and the body stores them very easily as body fat...

Umm, yeah, there is no metabolic pathway for the human body to store the full calories of dietary fat as body fat. We can store protein as body fat after converting it to glucose. We can store carbohydrate as body fat after converting it to glucose. We can't store dietary fat as body fat, although we can store a small portion of the fatty acids -- called "glycerol" -- in body fat. Ketones are used preferentially for energy by your body, and cannot be absorbed by your fat cells. But because your caloric needs are being provided by ketones, your body can store the glucose from gluconeogenesis of proteins and breakdown of carbohydrates into glycerol and glucose in your fat cells as triglycerides.

Now to address the specific points of the article:

Proponents say these diets also change your metabolism so your body breaks down more fats, and--voilà--fewer of the calories you eat are stored as flab.

Actually, this person is engaging in a straw-man hypothesis here. There is no magic changing of your metabolism. Converting proteins to glucose is a more "expensive" chemical reaction than converting carbohydrates to glucose. And only the glycerol portion of a fatty acid can be converted to glucose; the rest is ketones which must be used for energy by the organs of the body or else excreted in the urine.

Excretion of ketones in your urine if you are a healthy non-diabetic is a clear sign that your body is using fatty acids -- either dietary or stored body fat -- for energy in huge amounts. That's the "metabolic switch" people are talking about. We're not "changing metabolism so our bodies break down more fats", we're eating more fat and protein, which are more biologically expensive to store as fat than carbohydrates are.

Low-carb weight-loss plans do work--for a while. Pounds drop quickly at first because burning stored carbs (called glycogen) releases water. Quite simply, you lose excess water weight.

True, but only for the first three to five pounds. Beyond that, it's stored body fat (and muscle, if you are not consuming plenty of protein). This is a classic case of telling part of the truth with a statement. The implication is that all or most of the pounds lost on low-carb are water weight, which is a clear falsehood.

Nutritionists say, though, that low-carb weight loss isn't metabolic magic, just the working-out of nature's first rule of weight loss: Eat fewer calories, and you will shed pounds.

This author ignores the key difference: low-carb eating allows you to eat more calories than caloric restriction while producing identical results. Yes, we burn more calories than we consume, that's why we lose weight. All else being equal, however, a low-carber will lose more fat, retain more muscle, and suffer less hunger than a calorie-restricted or low-fat dieter on the exact same amount of calories per day.

That is the metabolic advantage at work.

Some low-carbers say this special way of eating eliminates cravings, but others feel headachy and nauseated.

I know of no low-carbers who stick with it for more than one month who complain of these symptoms on a regular basis. Then again, it may be that those who suffer these symptoms are unlikely to stick with it for more than a month. And the fact is, I got headaches before I started low-carbing; I get fewer now, but I still get them.

Burning far [sic] without carbohydrates produces substances called ketones, which can decrease appetite, but there's a danger because sustained high ketone levels may deplete mineral stores in bones, leaving them fragile.

The author gets the facts wrong again. If you are burning bodily fat in any way, shape, or form, you are producing ketones and using them as fuel. The kidneys only filter ketones out of the blood into your urine if you are producing huge amounts of ketones. Ketones are a natural body fuel, and any person who is losing fat is producing and consuming ketones, whether on a low-fat, low-carb, or calorie-restricted diet.

High ketone levels only deplete mineral stores for Type 1 diabetics. Once again, someone confuses ketoacidosis with ketosis/lipolysis. They are metabolically opposite processes; ketoacidosis is caused by wildly high blood sugar resulting in extremely acidic blood and is a life-threatening condition, while ketosis/lipolysis is caused by your fat cells giving up triglycerides, and by digestion of fatty acids from dietary fats with no profound health implications. Ketosis/lipolysis caused by reduced carbohydrate consumption does not cause bone loss. That's a stupid extrapolation from studies unrelated to a low-carb eating regimen.

...both groups achieved nearly identical weight losses after one year.

Unfortunate, but true. All eating plans to lose weight are hard. Although several have shown Atkins to have the highest retention rate, you're talking only a few people out of each sample group who will stick to any eating plan. However, you can be certain that with identical weight loss, the low-carber ate more calories than the low-fat or calorie-restricted dieter. And there's a good chance the low-carber has more muscle left at the end of the year, too.

When researchers at the National Weight Control Registry looked at the diets of 2,681 successful dieters who had maintained at least a 30-pound weight loss for a year or more, they expected to see many low-carb diet adherents. They were shocked to find just 25, or 1 percent of the total group. Their conclusion: Low-carb plans didn't produce a lasting metabolic change that kept pounds off.

Umm, that's not the conclusion I'd draw at all. We have thirty years of the low-fat mantra being pushed at the American population. In my opinion, we have this fact to thank for the current obesity epidemic. People are trying to reduce their animal fat consumption, and as a result growing obese on overwhelming amounts of carbohydrates trying to make up for the lost flavor and satiety. 1% of the total group is much more likely to be due to low-carb being extremely unpopular more than any other factor.

Oh, and we've already debunked the whole "lasting metabolic change" straw-man. No low-carber claims that eating low-carb will change your body so that you can go back to your old eating habits without gettinig fat again.

Unlimited access to bacon cheeseburgers is tempting,...

A bacon cheeseburger is off-limits to an Atkins dieter, too. Duh. Huge bun, enormous amounts of carbohydrates, ketchup with high-fructose corn syrup in it. Leave off the ketchup, leave off the bun, and it's OK, but then it's no longer a bacon cheeseburger.

...a low-carb diet that's essentially an all-you-can-eat saturated-fat buffet may increase your risk of heart attack and stroke, the American Heart Association cautions.

The only reputable studies evaluating saturated fat consumption have been done in the presence of a high-carbohydrate diet. Yes, I agree, if you eat a lot of carbohydrates AND a lot of saturated fat, you're in trouble. That's the typical American diet right now, and it's killing people left and right from diabetes and heart disease. I maintain, however, that it's the overwhelming consumption of 300+ grams of carbohydrate per day -- or more! -- that is killing Americans. It's that "high-everything diet" that's so unhealthy.

All that sat fat can raise levels of heart-threatening LDL cholesterol--and at the same time shortchange you on the antioxidants from fruits, veggies, and grains that protect arteries from plaque formation.

LDL is not the threat. Small, dense LDL is the threat, and high amounts of saturated fat in a low-carb diet have been demonstrated to raise levels of large, fluffy LDL which are no health risk at all, while reducing quantities of small, dense LDL which are the actual risk factor in LDL levels.

Low-carb diets are also high in protein, which makes them risky for people with diabetes because they can speed the progression of diabetic kidney disease.

If you are already in acute kidney failure, urea buildup from protein consumption will kill you between dialysis treatments. If you are not already in acute kidney failure, low-carb diets pose no additional risk of kidney failure! In fact, it appears that "diabetic kidney failure" is due to out-of-control blood-sugar levels, not out-of-control blood-protein levels. The high blood sugar destroys the kidneys; protein intolerance due to urea buildup is just a side-effect as a result of eating a diet high in carbohydrates.

Low-carb eating is proven to keep blood sugar in control and is endorsed by the ADA for diabetic blood sugar management. Low-carb eating prevents diabetic kidney damage in the first place.

Many low-carb products undermine weight-loss efforts because they're packed with as many--or even more--calories than "regular carb" versions. Many are also higher in fat. This is especially true of reduced-carb comfort foods such as ice cream, bread, pasta, and snack bars.

True. Off-the-shelf low-carb products often defeat low-carb dieters because those products aren't actually low-carb. For instance, numerous so-called "low-carb" bars boast 20 grams or more of carbohydrate per serving, and claim that because those carbohydrates don't raise blood sugar, the low-carb dieter should not count them. This is false advertising. Advertisers preying on ill-informed consumers is an age-old problem. Is this the fault of low-carb dieting?

No. These products contain enormous amounts of carbohydrates and attempt to pretend they're low-carb by ignoring the low-glycemic carbs. THESE PRODUCTS ARE NOT LOW-CARBOHYDRATE PRODUCTS. Stick to whole, natural foods on your low-carb regimen -- as recommended by Dr. Atkins in his books -- and you'll experience much better success than eating so-called low-carb junk food that gives you explosive diarrhea.

"It's the calories, not the carbohydrates," notes Robert O. Bonow, M.D., former president of the American Heart Association. "America is gaining weight because people are eating more calories than they can burn and getting less exercise."

Actually, as already mentioned, there is a metabolic advantage to low-carb allowing individuals to eat more calories on low-carb than on a low-fat or low-calorie plan and lose an equal amount of weight while retaining precious muscle mass.

Low-carb junk food is still . . . junk.

I agree, and such foods have no place on the plate of anybody interested in losing weight. But low-carb junk food is not the fault of the low-carb diet.

This anti-low-carb smear piece is appallingly poorly-researched and inaccurate. I'm amazed it ever saw print.

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Typical anti low-carb

Typical anti low-carb nonsense. These people learn this stuff from a magazine or classroom and simply regurgitate it. They never seem to wonder if the low-carb camp has a different opinion and why. Great rebuttal.
Mark