One common question that I get asked is: Is there a target or ideal weight I should shoot for?

Unfortunately there is no easy answer to that question. There are, however, several frameworks and benchmarks you can use to help guide your efforts.

The first thing you should know is: Science can't tell you what you should weigh.

Generalizations about height and body weight as are used in the Body Mass Index (BMI) calculation are meant only to inform scientists of population health trends, and are not supposed to advise an individual person about his or her health status.

For example, at my height (5'5″) a "healthy" BMI could be considered anywhere from 111 to 150 lbs. Not only does BMI not care that I am a woman and that I have a small frame, but it is inconceivable that my weight could fluctuate up to 30% and not have a dramatic negative impact on my health, as the BMI suggests.

Your BMI tells you almost nothing about your nutritional status, body fat percentage, or strength, and therefore tells you almost nothing about how healthy you are (or aren't). It doesn't even come close to giving you a sense of what proportion of your weight is visceral fat (dangerous), subcutaneous fat (only problematic at higher levels) and brown fat (metabolically advantageous).

BMI is particularly unhelpful if you are near any extreme on the height or size scales, for instance if you are very tall, very small, or very muscular.

Most of the critiques I've seen of BMI suggest that the measurement tends to give people a false sense of security about their health level. In other words, your BMI is likely to indicate that you are healthier than you really are, as opposed to the other way around.

But again, this tells you nothing about your personal health status.

The second thing you should know is: the scale can't (and won't) tell you if you're healthy.

Taking this argument one step farther, your body weight alone is also a very poor measure of your health. In fact, it tells you even less about your health status than BMI, which at least also accounts for height.

So the question, "What is my ideal weight?," is fundamentally flawed. Because the answer is, well, "It depends." And it depends on a lot.

"Health" is a vague term, since it can be applied to so many different aspects of your physical well-being. For the sake of this article I'm going to assume that for most of you "good health" means feeling energetic, physically able to do everyday tasks with ease, clear minded, and devoid of any physical illness or disease. I'll also assume that your idea of good health means maintaining this status for as long as possible into old age.

Obviously you may have different, more specific goals. Athletes typically have performance goals that would require accounting for much more than I've listed here. On the flip side, if you have a chronic disability your goals should be adjusted to account for limitations outside of your control.

You may also have vanity goals, which is perfectly fine in my book so long as they aren't tied up in your sense of self-worth. If your life is easier at work or in the dating scene in your city when you look a certain way, don't let anyone tell you that isn't a valid reason to keep tweaking your healthstyle until you're happy. Life should be awesome, and you should do what you can to make it that way.

But none of these goals can be defined by the number on the scale, so focusing there is not the right way to start.

What does matter is how you feel.

No matter what you weigh, if you aren't getting the majority of your calories from Real Food, exercising vigorously 3-5 days per week, avoiding prolonged periods of sitting, getting 7-9 hours of sleep, and maintaining strong social relationships, then you could be healthier.

Don't use a number on the scale as an excuse to drink soda or avoid strength training. That isn't how it works.

If you're doing all these things you'll probably find that you feel healthy. You will have steady, strong energy throughout the day. You'll have fewer cravings for sugar and not mind parking farther away or taking the stairs. You can zero in a bit more by having your doctor test your nutrients and blood lipids, but that's about as good as you can do.

Congratulations. Get on a scale, you're now at your ideal weight.

I define "ideal weight" as the weight you're at when you're doing everything you can to promote good health. It's where you settle at naturally from incorporating these behaviors into your life. For every person there's a range of weights which are near ideal, probably within 5-10 pounds (but I'm only speaking from experience, science doesn't know this for certain and neither do I).