But the king of scientific data -- empirical observations -- suggests otherwise. For the past two years, I've pretty much eaten whatever I wanted at the time and haven't followed any specific dietary regime, and I'm leaner and fitter than I've ever been. I'm 128 lbs and 18.5% body fat -- down from around 22-24% when I was eating Paleo. I can do five pull-ups, hike 3500 vertical feet per hour (at sea level), deadlift 160 lbs, and military press 75 lbs.
I cut out 90% of grains and refined sugars from my diet for the better part of three and a half years (February 2009 through December 2012). Throughout that entire time period, the changes in my fitness levels and body composition came almost exclusively from physical activity. In general, I was hovering around 23% body fat and weighed between 135 and 145 lbs. I slimmed down to about 130 during Field Camp (for those non-geologists, Field Camp basically involves spending a month hiking around and making geologic maps of an area), and then again during/after my expedition to Aconcagua. Overall, though, nothing changed dramatically.
After I got back from Aconcagua, graduate school happened and I pretty much just ate whatever was convenient. I didn't regain much of the weight I lost on that trip -- probably because I forced myself to work out for at least an hour, five days a week, to deal with the stress of writing my MS thesis.
I reached an all-time low of 127 lbs in the summer of 2014 (and I've been within 5 lbs of that ever since), and my speed in the mountains improved dramatically.
I don't know what the missing puzzle piece is, or if it was just one thing. But I do know that my endurance levels have skyrocketed. I don't struggle to keep up with people in the mountains anymore -- I'm kicking everyone else's ass.
What I'm doing now works, so I'm going to keep doing it.
Empirically, the two things that seem to be the key to getting leaner, and doing it quickly are:
1) Physical Activity. This is likely equally physical and mental -- if I've had a bad day at work, hitting the stair master or throwing some weights around in the gym clears my head. Reduced stress leads to reduced levels of cortisol and... you get the picture.
2) Cutting back on the booze. I love beer, and I love having friends who I actually want to go grab a beer with. I love experimenting with cocktail recipes, making liquor infusions, and trying different whiskies. Craft breweries and craft distilleries are a part of Seattle's culture. But beer and liquor have a lot of calories, and studies have shown that giving up booze for a month leads to a dramatic reduction in liver fat, which, in turn, helps the body metabolize nutrients more efficiently. Overall, as cliche as it sounds, moderation is the key.
Totally non-paleo post-workout meal: angel hair pasta with spinach, mushrooms,
grape tomatoes, and chicken sautéed in pesto sauce and topped with parmesan cheese.
I'm not sure what was inherently appealing about the Paleo Diet, aside from the link to evolutionary science. Perhaps it was the fact that it refuted the mainstream and pseudo-scientific claim that a vegetarian diet was inherently healthier than one that included meat. Perhaps is was the fact that it seemed to be adopted by athletes like powerlifters and MMA fighters, whereas the low-fat/vegetarian diets seemed to be more commonly associated with the women in color-coordinated workout outfits who read Shape magazine on the elliptical and then wave around pink 5lb dumbbells randomly and call that a workout.
As for CrossFit -- well, I started doing CrossFit because I was eating Paleo. They don't call it a "lifestyle" for nothing -- but that's true of any sport. If you want to excel at what you do -- whether that's cycling, olympic weightlifting, martial arts, hockey, or mountaineering -- you have to tweak your training regimen for your specific goals, and you have to have a diet that fits that training regimen.
While I don't follow the Paleo Diet anymore, or do CrossFit, both of those things were still beneficial for me.
1. I think certain endocrine functions were probably improved by the extended periods of time I spent eating less than 100g of carbohydrates a day, and by cutting sugar out.
2. I have a fat-adapted metabolism. Even though carbohydrates provide a lot of quick energy and are more easily digested at high-altitude, being able to use fat as a fuel is crucial in any endurance sport, especially mountaineering.
3. I understand the importance of good form when lifting.
4. I spend more time in the gym doing dynamic lifts instead of isolation exercises. Looking muscular is great and all, but being able to back up that look with actual abilities is better.
The Paleo Diet works for a lot of people -- I'm not denying that. I even have family members who have halted and reversed pre-diabetic endocrine conditions by eating low-carb, mostly Paleo diets. It just doesn't work for me. As a scientist, the only way I can figure out what works is by experimenting.
