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4 Weight-Loss Myths

Believe the myths, and despair?

Charlie Martin


June 15, 2013 - 11:30 am

The hypothesis: a slow carb diet with intermittent fasting, along with continuing to work for greater integration of exercise into my daily life, will help me lose weight and improve my still-too-high blood sugar. This is the third experiment of a 13 weeks duration, in an ongoing series. Follow my daily updates at Facebook and join me on Fitocracy to follow my progress there, of which there will be some. Honest.


13 Weeks: Season 3, Week 3

I’ve been personally interested in weight loss and associated things pretty much my entire life. Long-time readers will remember me mentioning being insulted about my weight — told I was repulsive, in fact — when I was seven or eight. I first started actively dieting, hoping to lose weight and not be repulsive, when I was about 12, and immediately ran into trouble with it. After a certain length of time, even strictly following a 1200 kcal a day diet, I’d stop losing weight.

Since this was well-known to be impossible, it must have been that I was cheating on the diet. I knew I wasn’t, but who’s going to believe a 12 year old?

Fast forward to when I was working on my PhD at Duke Medical School. By this time I was considerably more sophisticated — well, except emotionally, I still felt basically that I was repulsive — and I had started reading seriously about weight regulation. I discovered that a whole lot of things I’d been told were absolutely certain, weren’t. Many of those things are still generally believed, and I think they keep people from doing what is useful, get them to do a lot of things that aren’t particularly useful, and frankly cause many people to despair.

Myth #1: The “Ideal” Weight Is Healthiest.

This one has made recent news. Our idea of what is an ideal weight comes originally from studies done by life insurance companies. The insurance company actuaries spend their time trying to decide how much to charge for an insurance policy, which is essentially a bet: you are betting the insurance company that you will die young, and the insurance company bets you will live to a ripe old age. (I’ve explained the basic math of insurance on PJM before.) So insurance companies, primarily MetLife, did studies in the ’50s and computed ideal weights from them.

These studies were very empirical, and they really were aimed entirely at determining how much to charge middle-aged white people for insurance. They did a good job of that, but they didn’t account for any number of confounding factors. However, once they had published the tables, these tables went from being essentially descriptive — “middle aged people seem to live longest in these height/weight ratios” — to be taken as prescriptive — “everyone’s ideal weight is given by these tables of height/weight ratio.” Now we define these “ideal weights” in terms of body-mass index, BMI, which sounds much more precise and scientific, but turns out to be simply a height/weight ratio.

Pretty much anyone can see that BMI is questionable — for example, a champion bodybuilder with a competition body fat of 3 percent may well have a “very obese” BMI. (On the other hand, it’s unclear that very low body fat is necessarily healthy either — in fact, we know it’s certainly not healthy for women.)

The problem is that epidemiology, the study of health and disease across large populations, keeps finding results that don’t quite fit this idea of ideal weight. Most recently, a study by Katherine Flegel and others published in January of this year showed that the notion of ideal weight was massively oversimplified. The study found two things: first, that for younger people, BMI doesn’t have any strong effects, and as you get older, the BMI associated with the least likelihood of dying increases.

In other words, if you don’t want to die the data suggests you actually want a slightly higher BMI as you get older.

What’s more, other studies say that BMI isn’t as good a predictor as simply the length of your belt — the larger your waistline, the more likely you were to have a whole lot of different health problems like type-2 diabetes. (This one does fit the bodybuilder example, too — bodybuilders do generally have small waists.)

Now, this can be taken too far — there’s no doubt that real obesity has bad effects on your health. (My knees would tell you that, if asked. And if knees could talk.) But the truth is that being a little overweight is either not harmful or may actually be helpful.

Myth #2: Your Weight Depends Only On Calories-In Versus Calories-Out.

This one has also come up here before. My own data, collected over more than six months and my first two 13-weeks experiments, has shown that it certainly doesn’t hold for me. Over the first about 10 weeks of my very low-carb diet, I lost weight much more rapidly than could be accounted for by a calorie deficit; since then as I crossed the Great Plateau, my weight loss has been considerably less than calorie deficit should predict.

Again, this is hardly unknown scientifically, going back to very careful studies of Pima Indians. In those studies, the subject literally lives in a big closed environment, and their food consumption and calorie output can be precisely measured. What they found was that in fact the body adapts to starvation; if you stay on a low calorie diet, your body will slow down to save calories.

Here’s how it works: your body needs a certain amount of energy every day, simply to keep your heart beating and your nerves nerving. That bare minimum is called the basal metabolic rate. What the Pima Indian studies showed was that when they kept to a low-calorie diet, their basal matabolic rate actually slowed down to try to match.

They saw what I’d seen in myself when I was 12, and am probably seeing now — their bodies could down-regulate to handle the lower calorie intake.

Evolutionarily, of course, our bodies don’t necessarily want to lose weight anyway — a fat person can still breed, and someone with a little extra fat is more likely to survive when the mastodon harvest is a little slim.

As with the BMI, this doesn’t mean that dieting is completely pointless — if you reduce calories enough you will lose weight. And eventually die. But it means that the well-meaning people who say “Oh, losing weight is simple — cut down what you eat and you’ll lose weight; if you’re not losing weight, you must not really be cutting back” are wrong.

And annoying.

Myth # 3: What You Eat Doesn’t Matter.

Myth #4: Fat in Your Diet Is The Only Thing That Matters.

Once again, the actual science doesn’t actually support this. We’ve talked before about the research Gary Taubes surveyed in Good Calories, Bad Calories and Why We Get Fat. Basically, there is a lot of evidence that for a large population, the people who have what’s called “metabolic syndrome” or “syndrome X,” the amount of easily available carbohydrates in their diets has a big influence on their weight, and on the progress of their metabolic syndrome into frank type-2 diabetes.

That population is relatively easy to identify — they tend (callback to myth 1) to have big waistlines, to put weight on near their bellybutton instead of on their … hips. Take those people off carbs, and many of them lose weight even at roughly the same caloric intake. Other indicators of general health, like blood pressure, average blood sugar, and fats in the blood — the “lipid profile” which includes total cholesterol, triglycerides, and the various lipid fractions — all improve, usually markedly.

Public nutrition authorities, however, have for various reasons been pushing a different idea, that it’s the amont of fat in your diet that really matters, and a grain-based diet is the healthiest.

Again, the science doesn’t seem to stand up very well. There has been some evidence that a very low fat diet can improve cardiac health in people with pre-existing cardiac disease. Dr. Dean Ornish is the most vocal proponent of this idea.

The thing is that there’s relatively little evidence that this is really a healthy diet for people in general, and having tried the Ornish diet myself, I can tell you that it really has some issues just in terms of compliance. There are only so many bowls of salad and unbuttered brown rice you can eat. What’s more, because these diets are extremely low in fat, they force you to be nearly vegan, and for most people this also means it’s hard to eat enough calories. You’ll certainly lose weight on an Ornish diet, but most people are hungry all the time.

But now consider what happens when people adopt these dietary recommendations. You naturally go toward eating more grains, which means eating more easily available carbs.

In other words, it’s very likely that at least for those people who have metabolic syndrome, the low-fat grain-intensive recommendations are actively harmful.

This isn’t scientifically certain, and in fact is rather controversial, but there is one very interesting point to note: the increasing “obesity crisis” correlated very well with the introduction of the low-fat, high-grain dietary recommendations.

What To Make of This?

Well, so now we’re certainly in a pickle, aren’t we? (Pickles do appear to be good for you, by the way.) But if low-calorie diets don’t work as advertised, and low-fat eating doesn’t work, how about going the other direction?

Well, my own experience is both good and bad. For my first 26 weeks, I’ve followed a high-fat, high-protein, low-carb diet, and a lot of the effects were good: I have lost weight, my blood sugar is much better, and my lipid profile is very good. Which is a big surprise when you realize that I’m eating what would be considered about the worst possible diet in that respect.

But after 26 weeks, I’ve stopped losing weight, dammit. It’s very hard to explain — my food diary shows I’m still at what should be a significant calorie deficit, I was very successful at cutting carbs, and hell, my blood sugar was down so far I was having hypoglycemic episodes. But my weight stuck at very close to 273 pounds, about 50 pounds more than I would like.

Okay, Charlie’s First Law of Change is that the only thing that can’t help is to not do anything different, so I’ve changed my diet, adding a little more carbs in the form of beans, and at the same time taking one or two days a week of near-fasting, targeting about 600 kcals a day.

This may be doing some good although it’s a little too early to tell — right now I’m losing weight at a rate of about a pound and a half a week. (The variance is smaller too, but it’s still around two pounds, so it’s really too early to say that there is any real effect.) On the other hand my blood sugar seems to be straightening out a little — I’m not having the real low lows.

I think the real key, though, is that the biggest myth is the idea that we really understand the whole problem of weight regulation. Pick any diet, and you’ll find people who have great success, and people who don’t.

Paying attention to the myths, though, when a diet doesn’t have the desired effects, we tend to blame ourselves. Better to remember that no one really understands this well yet; if we try something, and it doesn’t work, it doesn’t mean we failed — it just means we’re not part of the group for whom that one notion worked. Give an approach a fair trial. Then if it fails, try something else.

Charlie Martin writes on science, health, culture and technology for PJ Media. Follow his 13 week diet and exercise experiment on Facebook and at PJ Lifestyle

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All Comments   (37)
All Comments   (37)
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How about testosterone and thyroid?

As I've posted before, I'm completely with you on virtually all diet points and personal experience. I only need to lose maybe ten to twenty pounds, but those pounds do NOT want to go unless I cut my calories below 1,000, then I can lose a couple of pounds fairly quickly, the problem being they come BACK even more quickly.

It is probably age, and probably boosting the aging factors like testosterone and thyroid would help. I also used to get way more exercise than my aging body will now stand for, others older than me are luckier in those regards, but even four hours walking does not impress my metabolism at all today, and I think it did twenty years ago.
1 year ago
1 year ago Link To Comment
One other thing, 3600mg of fish oil sounds like rather a lot (especially if you eat some actual fish once or twice a week not to mention other n-3 rich or boosted foods), if you need that much you are probably getting more n-6 than you need as well.
1 year ago
1 year ago Link To Comment
You tried the Ornish diet and ate salads and bowls of unbuttered rice? That isn't the Ornish diet. Not by miles.
1 year ago
1 year ago Link To Comment
You called your diet low carb, high fat, and high protein. The correct low carb diet is moderate protein. You are probably aware of the Jimmy Moore blog. A year ago he discovered his low carb diet was too high in protein; the excess protein was being metabolized like carbs.
1 year ago
1 year ago Link To Comment
Dunno, Charlie. Slow and sure is the best approach, I guess.

A guy called Mike Geary has some interesting ideas about health, fitness and so on. No, I'm not a 'marketing associate' of his, but he has a web site with some interesting theories. He's an exercise freak, lives in Colorado. Might be interesting for you to get in touch with him.
1 year ago
1 year ago Link To Comment
It would muddy the waters of the current thirteen week experiment but you might want to try some fish oil supplementation. Neither Gary Taubes nor Tim Ferris spend much time on the omega3/omega 6 imbalance that is a consequence of the graincentric American diet but there are Paleo and Primal people who focus on it as a major metabolic sticking point.
1 year ago
1 year ago Link To Comment
Tom, I/ve been doing 3600 mg a day all along.
1 year ago
1 year ago Link To Comment
Pretty much the same experience here. I'm 70, 6'2' and have a 43 inch waist. I'm down from 215 dropping agricultural grains and plateaued at 189. I go up to about 193 if I get my exercise disrupted by things like a cold then back down to 189, but no further. Like you I am using the 5:2 diet - 2 non consecutive days semi fast of 600 calories. Too soon to tell if i can break the 189 barrier. Michael Moseley's BBC/PBS doco Eat, Fast, Live breaks out the research on various forms of fasting including 5:2. Good luck breaking the barrier.
1 year ago
1 year ago Link To Comment
Charlie, You might need to take a vitamin/mineral complex to help with weight loss. Trace elements like Chromium and Selenium affect blood sugar and weight loss -- and Americans are chronically short on both.
1 year ago
1 year ago Link To Comment
I've used the low-glycemic diets off and on for a decade with good success. In my experience, occasionally you will get stuck, but if you stick with it, the decline will eventually resume. You're doing the right thing - add some moderate glycemic carbs, like beans, for a couple of weeks, and then go back to the stricter version. That way, the stall is more bearable.

I would not introduce high-glycemic carbs once a week. They cause no long term damage, but, again in my experience, every time I do that, I get a stall of three or four days in the downtrend.

A pound and a half a week is great, and just what you want, if you want to keep the weight off. After all, if you are looking for a 50 lb loss, that's only eight months!
1 year ago
1 year ago Link To Comment
Are you doing any exercise? I think in one of your previous articles you mentioned martial arts and weightlifting. For the longest time I had trouble fitting in a substantial daily weightlifting session just because of my work schedule, but I started doing 20 minutes in the morning and 20 minutes plus a little extra after work. I would just use a couple dumbbells in front of the TV so I didn't have to head out to the gym. Even though it wasn't much, it was still a big help.
1 year ago
1 year ago Link To Comment
Just by the way, my weight today was 269, which means I'm actually sustaining something close to 2 pounds a week for two weeks now. (Actual slope of the linear fit is -0.248 lb/day). Also, the standard deviation is down from last experiment -- 1.96 vs 2.3 -- and this is now around 3 sigmas down from the start weight. Still too little data to draw a conclusion but it begins to look significant.
1 year ago
1 year ago Link To Comment
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