Three Months of Intermittent Fasting, Developer Edition

Why I Started

My weight had crept up to 78.3kg. At 174cm, 78kg puts you right at the edge of overweight. I'd look in the mirror and think I looked fine, but then a photo would surface and I'd think "is that really me?" I was already going to the gym, but the problem was how much I was eating. Late-night snacks after overtime. Fried chicken to celebrate a deployment.

Increasing exercise had a time ceiling, so I decided to go after the diet side. But calorie counting was way too tedious. Hence intermittent fasting. You just set a window for eating -- simple.

I Went with 16:8

Eat during an 8-hour window, fast for 16. My eating window was noon to 8 PM -- water and black coffee only outside of that. I figured it'd be natural since I already skipped breakfast anyway.

But the first week was rough. By 10 AM I'd be so hungry that I couldn't focus on code. PR reviews especially suffered -- it's hard to concentrate on someone else's code when you're starving. (My review comments getting sharper might have been the fasting talking.)

Lost 2.7kg in the First Month

78.3 down to 75.6. A decent chunk of that was probably water weight, but visible changes are motivating. My pants fit a bit more comfortably.

The problem was weekends. Friday night drinks would lead to ramen at 2 AM, then Saturday morning hangover food. My weekend fasting success rate was 31%. All the weekday discipline crumbled on weekends.

The Disadvantages for Developers

Overtime is the wild card. If I need to stop eating by 8 PM but an emergency deployment gets scheduled for 7, I can't eat dinner. Deployment wraps up at 9:30 -- if I don't eat, I can't sleep from hunger; if I do eat, I've broken the rules.

I eventually made overtime days an exception. About 3-4 days a month. Setting it as an explicit rule actually reduced the guilt.

Caffeine timing was also a problem. Black coffee is allowed during fasting hours, but afternoon coffee wrecks sleep, poor sleep increases appetite the next day, and the vicious cycle begins. It took about six weeks to break. I set a rule: no coffee after 2 PM.

Hit a Plateau in Month Two

75.6 to 74.9. Just 0.7kg in a month. Barely anything. Whether my body had adapted or I was just binging on weekends, I couldn't tell. I almost quit at this point. "Maybe this doesn't actually work."

But even though the scale wasn't moving, I could feel body fat decreasing. My belt went down one notch. That's when I learned not to obsess over the number on the scale.

Three-Month Results

78.3 to 73.8 -- 4.5kg total. Not fast, but it's stayed off without any rebound. Body fat went from 23% to 19.7%. (Though I'm a bit skeptical about the accuracy of InBody machines.)

As for developer focus: once I adapted, the morning fasted state actually felt clearer mentally. My experience is that fasted focus beats the post-lunch drowsy state. But this varies by person. If you get hypoglycemic, it could be dangerous.

Am I Still Doing It?

Weekdays, yes. Weekends, loosely. Not a strict 16:8 -- more like 14:10. If you try to follow it perfectly, the stress makes it unsustainable. "Roughly following it for a long time beats perfectly following it for a short time" is the three-month takeaway.