Unhealthy People Eat Meat

Once in a while a study will come along that suggests that meat consumption reduces lifespan and increases incidence of disease. These studies are usually performed by asking people what they eat periodically and then taking note of when/how they die.

"People who eat meat die more quickly." Let's unpack that. Does that mean eating meat causes you to die earlier? What about this statement: "People who watch reality television have higher credit card debt." Does this mean watching Survivor will affect your credit score? Perhaps, perhaps not. Perhaps, poorer populations are more likely to watch reality television, and poorer populations are also more likely to have credit card debt.

So what else could these studies mean? It could mean that people who have overall bad diets/habits both eat more meat and die earlier, even if eating meat and mortality are unrelated (or even positively related). People who are more conscious are more likely to eat more whole foods, in addition to less meat because the common knowledge is that meat is bad for you.

If at some point, correctly or not, people determine something is bad for you, the claim eventually will prove itself. People who follow nutritional advice and watch what they eat won't eat it, and will live longer. People who don't care about nutrition will still eat it, and they will die earlier. Both will occur whether the "bad" food is really bad or not.

This has two implications. First, observational studies (that is, studies where scientists simply observe how people act) on diet are completely unreliable and perfectly useless except perhaps as the precursor to a controlled study (a study where all possible confounding variables--like an overall healthy lifestyle--are controlled for). Secondly, it puts an enormous amount of weight on the decisions of nutritional experts. One bad call will echo for as long as you let it.

Four Pillars

I posted the study about the mice first, but really the first study that started to convince me was this one. It is an analysis of a multitude of previous studies about saturated fat and heart disease. Its conclusion is that there is no measurable relationship between saturated fat and heart disease.

I saw this and my jaw dropped. WHAT? This is supposed to be a foundation of nutrition! Saturated fats bad! Unsaturated fats good! Right? I consider myself a nutrition geek, so how could I be wrong about this?

Maybe it was a bad study. Maybe there's something they missed. But the more I look back at studies which have supposedly demonstrated a heart disease/saturated fat link the more those look like bad studies.

I'm not convinced yet. My beliefs have too much intertia to be swayed yet. But I have to take another look at things. Here's what I still believe and have for some time:

1. We should eat like our ancestors ate
Not much evolution has taken place since prehistoric times, so we're probably designed for a diet not unlike that of the stone age.

2. We should eat "whole foods"
No, I'm not talking about the overpriced grocery chain. The more processing food goes through, the more components it has, and the more additives it contains, the less we control what we're eating. Period. And, as a corollary to 1), our ancestors didn't eat McNuggets and Cool Ranch Doritos.

3. We should enjoy our food
What is the point of eating something for good health if it isn't delicious? Are the extra years of life really worth it? Food is an enormous part of life. It brings us together, it affects our mood throughout the day, it forces us to sit and slow down for a few minutes.

4. Convenience should be the least consideration
Food is life. It is health. It is happiness. It is not just another of life's unavoidable burdens. If anything is worth spending a little extra on it's good food. Even if you don't love food like I do, from a purely fiscal perspective good food will reduce your medical bills down the road.

During a time where my secondary beliefs about food (saturated fat is bad, all calories are created equal, animal products are evil) are coming into question, these primary beliefs are all the more important.

Of Mice and Men

Take a look at this graph. Ok, it might need some explanation. In a 2006 study some scientists took some identical mice and put them into four groups. One group ate normal mouse food (chow). One was fed high-sugar, high-fat chow (marked as simply high-fat). One was fed a low-carbohydrate, higher-fat diet (ketogenic). The last group was fed a restricted calorie diet that only contained 66% of the calories of the regular chow but was otherwise the same.

Based on what I thought I knew about how diet works, the group that stood to lose the most weight was the calorie-restricted group, followed by the regular chow group, the low-carb group, and then the high fat/sugar group, who I figured would gain the most weight. The high fat/sugar group did gain the most weight. However, the low-carb group and the low-calorie group lost the same amount of weight.

It wasn't that the low-carb group didn't like their new food and ate less. The study carefully controlled the number of calories--all the groups ate the same number of calories except for the reduced-calorie group. Replacing carbs with fat led to weightloss--the same weightloss seen in reducing total calories by a third. Unlike with a similar human trial, the mice couldn't have cheated. They couldn't have been sneaking food or hiding food or what have you.

If you take away someone's calories, of course they will lose weight. But they're going to be tired and cranky and eat as much as they can as soon as they can again. They'll gain it all back. Then there is the idea of a metabolic advantage, which is the suggestion that certain diets simply cause higher calorie burning regardless of similar caloric intake. This study suggests low-carb, high-fat diets have that metabolic advantage.

I've been reading all sorts of biochemical explanations of why this would be the case, involving insulin and glucagon and lipase and I admit I don't really understand it. But the evidence I've seen of the benefits of a higher-fat, lower-carb diet is mounting. So, I've decided to try it out myself. I'm a pretty healthy person, young, with a BMI of about 19, no major problems, so I figure there isn't much risk of damaging myself too badly.

This blog will serve to chronicle my experiences with following the recommendations of these low-carb advocates (which end up being quite a lot more than just "eat fewer carbs").