I remember when I first heard about the Atkin's diet. The tag line I heard repeated by so many people was "eat as much as you want and lose weight". This started a LONG debate as to whether there was a way to eat an elaborate amount of food, albeit low carb, and still lose weight. The immediate challenge to this argument came from the medical establishment that argued:
- if you truly eat excessive quantities of food, where do the calories go? The calories cannot vanish. They either have to be burned up or stored in the body (most often as fat). There is one other option: that they never get absorbed. In other words, if you truly could eat as much you want and lose weight, it might be that your body doesn't succeed in breaking down the food and just let's it pass out through your intestines and ...
- In diets like Atkin's, your diet becomes much more based on animal proteins and fats. Especially 30 years ago, the idea of eating MORE fat was heresy. The medical community as a whole believed that such eating.would increase the risk of heart attacks, stroke, cancer and more.
- This is a non-sustainable diet. People will not manage to stick to such a low carb diet for very long. In the meantime, they will have developed "horrible" eating habits.
This is not a complete list but you get the picture. And the arguments are good ones. Let's work through them and try to get a perspective on the whole idea of satiety (satisfaction from a meal) and food quality (can you be healthy while eating steak all the time).
First of all, it is very hard to ignore the great number of testimonials by people who have switched to low carb diets and managed to lose weight. On the other hand, you have to be VERY careful with testimonials. EVERY diet and exercise plan will find a 100 people who have succeeded with it. And when you hear 100 people one after the other say "it works", it is hard to ignore. But the real question is how many TRIED these plans. If 10,000 tried a plan and only 100 succeeded, then that means that 99% failed !! Nevertheless, there are quite a number of research studies published in respected medical journals that have noted the success of low carb diets. So, it is fair to say that there is at least some basis to the argument that low carb works. So this brings us back to the original question: if you can eat endlessly, where do the calories go ?
Another point I want to raise harks back to the theory behind low carb diets like the Paleo diet. The argument here is that we have been genetically selected to eat as did the cavemen. But something seems strange about this argument. In a harsh reality of dinosaur filled streets, it was critical that food never got wasted. There was no refrigeration so it was hard to store up for the winter or for periods of famine. So, if cavemen could eat low carb diets, as much as they wanted, and never gain weight (i.e. not put on fat), then all of the food they caught would be mostly wasted. They could potentially eat an entire T Rex yet have not stored any of the extra calories for times when T Rexs are in short supply. Evolutionary speaking, this would be terrible. So, it MUST have been possible to eat excessively when food was available and then to store the excess calories at least to some extent, as fat, for times of need.
There have been formal studies trying to see where the calories go when people eat low carb diets. Some studies did NOT show any real difference in metabolic rate, i.e., our baseline burning of calories when we are not actively exercising or being active. In other words, there was no evidence that low carb diets made you burn more calories (and thus did not store them as fat). A recent study that made quite a few headlines DID show that patients on low carb diets burned more calories at rest. So, it DID seem that eating low carb has a benefit in reducing calories available for storage as fat.
The answer to the benefit of low carb seems, at least partially, to be due to the effect of such eating on one's appetite. Almost everyone has experienced days when they just had no taste for any food. Looking at a doughnut made them queasy and smelling a steak made them run. So imagine if a style of eating suppressed your appetite to such a point that you would lose the desire to eat after eating a relatively small amount of food. Or better, what if you walked around all day feeling "full". Would it matter if you had eaten 2000 calories or 10,000 ?
What does appear to be true is that low carb eating decreases appetite. So, when you tell a low carb eater to eat all they want, they do. But the lack of carbs in their diet seems to suppress appetite to such a point that they eat much fewer calories overall, without really noticing and more so, without counting calories. Most importantly, this type of eating less does not cause hunger or cravings.
Why is this ? Many believe that it is our old friend Insulin that is responsible for a good part of this. When we eats carbs, it spikes our production of Insulin which then triggers our bodies to shuttle the sugar into our cells. However, there seems to be an overshoot effect such that big spikes in Insulin, triggered by high sugar loads, cause a bounce back effect where the blood sugar levels dip too low. And THIS triggers a hunger response leading the person to eat more food.
Of course, if this is the whole picture, then one could play with their diets in such a way that the carbs eaten lead to smaller spikes in Insulin. And there is no reason why this approach would not work, according to the same logic as above. The low carb camp would argue that trying to keep Insulin minimally stimulated requires the abandonment of carbs. And from here, you can already see why there is such a fundamental dispute amongst the different carb camps.
Let's also be clear that low carb diets are NOT magic. There are many people who fail to stay on them. Cravings for carbs is real and there are some people, no matter how low carb they go, who will simply not be able to resist a doughnut. This is NOT a will power issue. There is something that we still do not fully understand that makes certain people react to food in the same way as drug addicts respond to their drugs. And we need to recognize this and respect this point before announcing that low carb diets will save the world.
What about the long term effects of eating steak every day ? Before I address this, I want to remind everyone that the message of low fat has not seemed to stem the growth of obesity and diabetes. So, no matter what the theory, we have to be open to the possibility that low fat diets are problematic and perhaps even at the core of our obesity. This means that the question is NOT "are steaks bad". The question is "are steaks worse than our present eating habits". And in fact, there is solid research that shows that low carb (hi fat) diets actually improve our blood levels of cholesterol and fats, and help control our blood sugar levels. Could it STILL be that steaks are bad for us, EVEN when our blood tests show we are healthier ? Sure, it's possible. But this is a difficult argument to make. And it is very hard to justify switching someone off of low carb when their cholesterol and blood sugar are all good.
We do not have all of the answers. But the truth behind the magic of low carbs seems to be a combination of things. Most importantly, for some people, it is a way to partake in foods they enjoy while not feeling guilty or hungry. And that really is an achievement.
One thing that we should ALL refrain from is laughing at the theories of the different diet camps. And on this, I will speak next time.
Thanks for listening