Hacker's Diet and Keto
TL/DR: the real secret to The Hacker's Diet is Walker was doing One Meal A Day (OMAD) before it was cool. This form of intermittent fasting is really, really good for steady weight loss.
The year was 1999, or something. I was struggling to understand weight loss and had been having trouble with simply “eating less” and losing weight. I had the Internet. I don't know how, but at some point I stumbled across The Hacker's Diet by John Walker, “founder of Autodesk, Inc. and co-author of AutoCAD”.
I read through Walker's guide to tracking your weight and calories and adjusting the calories in such a way as to maintain a 10% weighted average weight loss over time. Weighing every day, tracking calories, and following his fitness ladder.
Here's the thing – this REALLY worked and worked well. All I needed was discipline and some tracking in a spreadsheet. I stuck with it for 1.5 years and lost 65lbs. This was a pretty big achievement for me at the time but it was very challenging and I was very obsessive about it all. I was going to university, had very little social life, and just stuck to my guns. I weighed my food, I skipped rope for 20 minutes a night, and I didn't drink beer (2 light beers on Saturday night). I lost weight steadily but more and more slowly as time went on, despite trying harder and harder.
Something happened, long story, and I stopped caring about my weight and went back to regular beers, pizza, and whatever else I felt like. I stopped all the intense cardio. I gained the weight back in about three months.
Fast forward several years later and I learn about the Ketogenic Diet. I noticed that the same thing happens: it works really well for a while then you get diminishing returns. And what do Keto people do when they stop seeing rapid results? They fast. Many of them go to an intermittent fasting routine with a fairly long gap between meals (e.g. only eating for 8 hours in every 24). Some of them go to one meal a day (OMAD).
Today, while sitting around with some friends while our children played, I was drinking beer and eating pizza again and thinking I should get back on my keto regime soon. For a while I've been trying to skip breakfast and this has been working well for me and is surprisingly easy. Out of the blue, I remembered The Hacker's Diet, and then I remembered a throw away tidbit from that venerable document.
For various reasons dating back to the lifestyle of programmers in the bronze age of computing, I have long preferred one of the weirdest meal schedules of all. I eat basically one meal a day, about 7 or 8 hours after I awake. I supplement this, on occasion, with a light snack a few hours later.
— How many meals, and when? in Planning Meals
Yes, Walker eats one meal a day. Wow. This was a throw away line in his document to illustrate how it doesn't matter when you eat, just that you controlled your calories per day somehow. His strange eating schedule is an example of how you can eat less by eating fewer meals.
This is the real secret of The Hacker's Diet!
And it is the real secret of Keto. Once you get to the point where you are plateauing with any diet, your only answer is to eat less. And the easiest way to do this is to not eat for a long time. If you try to just have smaller meals (or, worse, more very small meals) you will be riding that wave of hunger/satiation over and over which leads to many more chances to overeat each day. It is far better to settle into hunger. As soon as your body figures out it isn't getting a meal until later, it fades away a little (talking about people who have access to food, this is not really hunger, it is more appetite and we are incredibly privileged to be able to feel appetite and not true hunger).