Weight loss or fat loss – which is more important? Its fat loss, for a few reasons.
Weight loss shouldn’t be your goal. Weight is a highly variable measurement of the human body and it really isn’t that good for most people’s purposes. For competitive athletes like runners, boxers, rowers, and cyclist, weight is extremely important, but for the average person, its just not that useful. First of all, expect your weight to fluctuate by up to five pounds or so any given day. This makes it hard to track progress, though by measuring daily and observing trends, we can get a picture of how your weight is changing. Is that really your goal though? I would guess that if you think your goal is to lose weight, what you actually want is to lose body fat. Weight doesn’t measure body fat – it just measures weight. So lets measure what we actually want to change, rather than some other measurement that correlates with it. Not to say you won’t lose weight while losing body fat, but gaining lean muscle mass may make it seem as though your results are less impressive than they actually are. The best method of testing body fat is in a lab, which is great, but a bit overkill for most people. Calipers, used correctly, are another accurate and cost effective method of measuring body fat. Recently, some at home scales are capable of measuring body fat fairly accurately as well, which is the easiest method (many will even track the results of it for your and upload them to your workout logs – technology is getting pretty great).
Its also a lot easier to sell weight loss than body fat loss. Most people know their weight, and can pick a goal weight (which does not have a close relation to what you want to look like at that weight – everyone carries weight differently. One person might look slim at 150 pounds, while another might look portly at the same weight – height, build, body type, and muscle mass all play a part in what you weigh and are all different for everyone.) Body fat loss is a little more abstract. What does 5%, 10%, 20% body fat look like on a person? These are hard to picture for the average person. We just don’t talk about our bodies using this (superior) measurement in casual talk with non-fitness minded people. We can talk about a goal weight casually though, and losing 5 pounds is easily quantified by friends and family, so we frame dietary changes in the paradigm of ‘weight loss’ and ultimately end up short changing ourselves. The takeaway here: Use body fat, not weight loss. Maybe your friends won’t understand, but that’s fine. Keep telling them about your weight loss in pounds if you have to, but you keep track of it through body fat (if weight loss is your goal).
For those of us who are underweight and want to gain weight, the reverse applies – you want to gain lean mass, not fat. Weight gain in general isn’t the goal. Weight gain here is accomplished by increasing weight while maintaining the same body fat percentage. If you do that, you gain lean muscle mass and look better at the end of the program. If you ignore whether or not the weight you gain is lean muscle or fat…well, it often doesn’t end well.
You’ll notice that I will use these two ideas interchangeably. This is for practical reasons, as using different wording than what everyone is looking for might confuse and turn off some people. Hopefully after reading this, you will know the difference and can help spread that information to your friends and family.