A few weeks ago my friend and fellow science fiction writer, Ramez Naam, posted a link to an article debunking some myths about bulletproof coffee. Then today I noticed a link on Reddit about a professor at Kansas State University who went on a convenience store diet eating Twinkies to prove that counting calories is what matters most in weight loss, not the nutritional value in food.

I am all for science, and I love to understand exactly how things work and why things have the effect they do. But often I think that in our zeal to get to the truth we overlook the practical question of what actually works.

Let me give you an example. If you ask a dentist whether it’s better to floss before you brush your teeth or after you brush your teeth, they’ll tell you it doesn’t matter. Both are equally effective at preventing dental problems. However, if you look at how many people continue flossing, that is, they stay in compliance with the regimen of flossing, then you find there is a difference. People who floss after they brush their teeth are more likely to continue flossing. (Sorry, I read this a year or two ago, and can’t find a link now.)

Why is this important? Well if you look at diets, the most important factor in weight loss is not how effective the diet is, but in how compliant people are. It’s easy to start a diet, hard to stay on it. Staying on it is the challenge for for most people.

Perhaps we could, in theory, eat exactly 1200 calories of Twinkies every day and lose weight, but in practice how likely are we to continue counting calories meal after meal, week after week?

I think the value that people get out of approaches like bulletproof coffee, low-carb diets, or other structural approaches to dieting (in which the emphasis is on eliminating certain foods rather than counting calories) is that for some people those diets are easier to stick with. This moves us out of the realm of basic chemical/biological science (which is how you might measure effectiveness of a diet), and into the realm of psychology (which is probably where the majority of compliance comes from.)

But even if we evaluate diets for compliance, it doesn’t mean there’s one best solution for all people. Some people might do really well with one diet, and other people do better with a different one. We all have different favorite foods, eating habits, and tolerance for eating the same foods over and over. For other people, a low-carb diet might work really well, others might like to replace breakfast with bulletproof coffee, still others use exercise, and some count calories, and some blend multiple approaches.

So when we see a piece of research that says counting calories is what matters most in weight-loss, we know that it’s wrong. What matters is the combination of compliance (whether people can stick to the diet for whatever period of time is necessary) and effectiveness (how much weight is lost when you’re in compliance.)

Yes, we need science and the understanding of fundamental principles and theory. But what also need to know is how things work in practice, and not just in a general population, but specifically for us.

The way we get there is through personal experimentation. Be willing to try something (within reason, of course) for a period of time and see how it works. If it doesn’t work for you, it doesn’t matter that science says that it works for 80% of people. It only matters that it doesn’t work for you. Learn that it doesn’t work, and then move on to a different trial.

Conversely if something is working for you, then it doesn’t matter if science can’t explain it. It’s working. Don’t mess with it.