A few days ago, CNN reported on a nutrition professor who lost 27 pounds in ten weeks eating mostly Twinkies (link). Not only that, but health markers improved too – LDL went down and HDL went up.
Some people seem to think the results resolve the old question of whether calories are all that matter in weight loss. After all, if you can lose weight by eating Twinkies, Doritos and Oreos, what else could it be than calories? Surely that's just about the worse diet you can have.
While I'm obviously a big fan of self-experimentation, I think the results have been misrepresented in some cases. What do I mean by that? Let's look at the experiment and the results a bit more closely. Here's a quote from the article:
For a class project, Haub limited himself to less than 1,800 calories a day. A man of Haub's pre-dieting size usually consumes about 2,600 calories daily. So he followed a basic principle of weight loss: He consumed significantly fewer calories than he burned.
If we take the 2,600 calories daily as the correct figure, then for the ten weeks, Haub was running an 800 calorie deficit. It's hardly surprising that he lost weight. When you cut back enough on your energy intake, you start losing weight – in this sense, a calorie is a calorie.
But since this is an experiment with only one participant, it's impossible to say whether more or less weight would have been lost if the diet had been different. Did all the sugar he was eating prevent him from losing the maximum amount of body fat? There's no way to tell.
There are some hints, however, that it's not all about calories. The amount of calories consumed may be the primary factor in how much weight or fat is lost, but that doesn't rule out other factors. In rats, for example, green tea increases weight loss during calorie restriction. The rats consuming green tea burned more of their body fat and absorbed less fat from the diet, despite eating the same amount of calories.
In real life settings, the argument that a calorie is a calorie is difficult to examine, because the number of calories we burn is not constant – it depends on many variables. We now know, for instance, that genetics play a role. Some people have a hard time putting on weight, because the more they eat, the more calories they burn. They may get an urge to exercise more, for example. And anyone who's tried different diets knows that some foods make you more energetic than others, despite having a similar number of calories.
But that's not all. Some people don't put on weight even when exercise is forbidden. Their bodies just start using all that excess energy in other ways: increasing metabolic rate, heat production, etc. Is a calorie really a calorie in this case?
Then there's the question of how to count the absorption of calories from different macronutrients. If you divide people into two groups and feed both the same amount of calories, but have one group eating more protein and the other group eating more carbohydrates, their weights will be different. In general, high-protein diets result in more weight loss than high-carbohydrate diets.
As you can see, the question is hardly as simple as some people make it out to be. And there are more similar things that complicate the issue. Stephan from Whole Health Source has a good post on the Twinkie diet and how it relates to hormones and fat mass regulation, and I'm sure there are other health bloggers who have picked up on the same article.
Putting the calorie issue aside, perhaps the thing that aroused the most interest was the part about improved biomarkers. Sure, you can lose weight eating a terrible diet, as long as your eating very little, but shouldn't that wreck your health in other ways? Apparently not:
Haub's "bad" cholesterol, or LDL, dropped 20 percent and his "good" cholesterol, or HDL, increased by 20 percent. He reduced the level of triglycerides, which are a form of fat, by 39 percent.
But that's not really big news. You see similar things happening in many studies where the participants are put on weight loss diets, regardless of what the diets are like. Even in the studies where overweight people are put on the conventional low-fat, high-carb diet – which is not really a good approach for improving cholesterol levels, glucose and insulin – these health markers improve while they're losing weight. As a spokeswoman for the American Dietetic Association says in the article:
"When you lose weight, regardless of how you're doing it -- even if it's with packaged foods, generally you will see these markers improve when weight loss has improved," she said.
However, as in the case of the amount of weight lost, there's really no way to tell based on this experiment whether his health markers would have changed differently on another diet with the same calories. Low-carb and low-fat diets have very different effects on cholesterol during a calorie deficit, for example (note also how the subjects lost more weight during the low-carb diet despite eating more).
Since the study only lasted for ten weeks, the fact that his LDL and triglycerides decreased while HDL increased doesn't say much about the long-term effects. I wonder what his cholesterol levels would have been after a year of following the Twinkie diet.
Also, there's more to cholesterol than just LDL, HDL and triglycerides. In the case of lipoprotein particles, size matters. A diet consisting mostly of sugary snacks is probably not going to do a whole lot of good for LDL particle sizes in the long run. And even when HDL and LDL levels look good on the surface, there's oxidized LDL and lipoprotein (a) to worry about.
What we can say with some certainty is that regardless of how you do it, returning to a normal weight seems healthier than being obese. In the maintenance phase, which lasts much longer, more things should probably be taken into consideration. Haub himself seems to have mixed feelings about his experiment:
"I wish I could say the outcomes are unhealthy. I wish I could say it's healthy. I'm not confident enough in doing that. That frustrates a lot of people. One side says it's irresponsible. It is unhealthy, but the data doesn't say that."
While the health markers are interesting, it would have been interesting to hear more about his experience in general. How did he feel before, during and after the diet? Was he feeling energetic or tired? How was his mood? Did he have any problems, digestion, bad skin, etc?
Before you kickstart your own Twinkie diet, note that professor Haub also had a multivitamin and a protein shake daily, which may have influenced the results somewhat. And if you've already tried a strange diet and managed to lose weight, drop a comment and tell us how it went.
For more information on diets and weight loss, see these posts:
Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?
A Year of Intermittent Fasting: ADF, Condensed Eating Window, Weight Loss, And More
Green Tea and Capsaicin Reduce Hunger and Calorie Intake
Green Tea Extract Increases Insulin Sensitivity & Fat Burning during Exercise
