Tuesday, July 21, 2015

The dreaded "Diet" post

This post is coming sooner than I thought, but we are starting to get some questions about weight loss. So here’s my general feeling about diet and weight loss. 
tl;dr - (1) Get as much sleep in the dark as you can, (2) eat a nutrient dense diet, then (3) work out in a smart weight-bearing, strength-focused way.
But everyone cares about my thoughts on diet, so here goes:

The Math

Warning, equations ahead!  Feel free to skip over them; you don't need them to understand the explanation. I need to put them there to satisfy the pendants who say “but, but, but…”
Everyone always says “change in weight is as simple as energy in minus energy out.” That’s not totally correct, but it’s pretty close. So let me start with a true statement:
ΔW = κ∫dt (Ein(t)-Eout(t))
ΔW is weight change
κ is ~0.000285 lbs/Cal (Food Calorie = 1kcal)
Ein(t) is the calories you intake
Eout(t) is the calories you output

To make it simple, let’s integrate over one day
ΔW = κ∫dt(Ein(t)-Eout(t)) = κ(Ein-Eout)
This is where everyone gets the energy in minus energy out thing. And really, it's the truth, you can't argue with thermodynamics.
The trouble comes because everyone thinks that energy in and energy out are independent (don’t influence one another), and people say things like: "Eat one fewer cookie a day (~100 Cal) and you'll lose 1lb/month" or "Stand instead of sit and you'll burn enough calories to lose weight."
Unfortunately our bodies have some really effective feedback mechanisms that make energy in and energy out nearly perfectly correlated (correlation time, τ, is about 1 day). So if you skip that 100 Cal cookie, you're going to eat a slightly bigger dinner without thinking about it. Likewise, if you stand instead of sit, you'll eat more too (without realizing it). If you try to force yourself to eat fewer calories and stick to it, then your body will adjust energy out to maintain homeostasis. That is, your body will lower its metabolism, either by moving less (sitting on the couch) or biochemically (by having your mitochondria become more efficient).
It's nearly impossible to win! Seriously!
Energy in is not only a function of what you eat, but it's a function of what you do.
Likewise, Energy out is not just a function of your activity, but it's a function of what you eat.
It's more like this:
ΔW = κ∫dt (Ein(Eat(t),Activity(t-τ))-Eout(Activity(t),Eat(t-τ)))
or more correctly, we'd have to integrate over τ too
ΔW = κ∫∫dτdt (Ein(Eat(t),Activity(t-τ))-Eout(Activity(t),Eat(t-τ)))
Ok, that should be enough to satisfy the most pedantic reader.

The Explanation

To paraphrase Gary Taubes: Overweight people aren't overweight because they eat too much, they eat too much because they're overweight.
When you're overweight, your hormones are all screwed up, which makes you hungry and eat more and which slows your metabolism down so that you can't burn more. Walking around the office or cutting out a cookie a day isn't going to change a thing. What you need to do is change your diet so that your body gets all the hormones balanced correctly.
As an example, take me (and I have a whole group of other people for more data points), I've always worked out really hard all through grad school, but my diet was pure crap, and no matter how hard I worked out I still slowly gained weight that whole time. Even after I was out of the stressful environment of grad school, I still was slowly gaining weight, even with a switch to a higher-intensity workout program. But as soon as I adjusted WHAT I ate (in fact, I eat more now than I ever did before), I dropped nearly 30lbs in a couple of months. I had no change in activity.
Think about it this way: If you run 10km/hr (think Bolder Boulder in 1 hour), that's only about 800 Cal/hr. That's about 1 meal’s worth if you believe the USDA recommendations. And no one is doing that every day. Your body is so efficient at turning stored energy into motion that truthfully your activity level barely matters (and I say this as a gym owner!). Your weight is mostly determined by what you eat (macronutrient ratios and food quality) and only slightly determined by how active you are. However, how active you are is determined by what you eat. People don't get overweight because they sit on the couch, they sit on the couch because they're overweight. Conversely, you know all of those studies that say that people who fidget a lot are less overweight? That’s not the fidgeting that’s causing them to be skinny, it’s their biochemical milieu that’s making them fidget to burn rather than store the energy.
Now does all of this mean that calories don’t matter at all? No, if you eat way more calories than you can burn (by becoming spontaneously more active or raising your metabolism), then it has to get stored as fat, but that threshold is pretty high. Excessive calorie restriction or over exercising is the way to permanent metabolic damage. What we want you to do, if you want to lose weight, is to eat enough to fuel your activity, but make sure those are nutrient-dense foods that are going to help signal to your body to burn, rather than store, your energy.

But what should I do?

Come talk to us! Everyone is different, everyone has different goals, and we don’t want to make broad recommendations without talking to you first. But, as you can see, we love talking about this stuff ad naseum. So find us at the gym, write us an email, whatever works for you. We’d love to help!
8 rounds with full recovery
3 deadlift
3 clean pull
3 close grip muscle snatch
3 squat
3 good morning