How I Lost 20 Pounds in 20 Weeks With My iPhone (or: Data is King)

Well, it was really more like 17 weeks, but who’s counting. ;) First, I’ll give the punchline.


Chad, you were skinny! Why diet?

  • High school: 140 pounds
  • College: 150 pounds
  • Grad school: 160 pounds
  • After four years at IMVU in delicious downtown Palo Alto: 180 pounds

At my height, 180 lbs. isn’t terrible, but the trajectory is obviously wrong. Without adjustments to my lifestyle, you can see what would happen. So I started paying attention.

In February, Laura and I got iPhones. Shortly after, I discovered Lose It!, a calorie-counting and weight-tracking app. I knew my eat-box-of-cheez-its-when-bored habit was bad, so I began simply tracking calories with Lose It!, hoping to break some bad habits. After all, if you give an engineer some data, he’ll optimize it.

A few weeks later, I ended up reading The Hacker’s Diet. It’s a quick, educational, and inspirational read. John Walker’s thesis is that anyone can lose weight if they correct the flawed feedback mechanisms causing them to eat more than they consume every day.

See, our bodies are complicated machines. We can’t entirely understand them, so we use models (created by people smarter than me) to help us predict how our bodies will behave under various inputs. Thus, there are tons of weight loss plans, and I’m sure they’ve all worked for someone: all raw, low-carb, no-carb, low-calorie, intense exercise, glass of red wine every night, protein shakes in the morning, seven snacks a day, etc. etc.

All of that is too complicated for me, so I chose the simplest model I knew: Calories In, Calories Out. It goes something like this:

The Hacker’s Diet (Theory)

(I am not an expert! This is what worked for me. Consult your nutritionist and physician. Don’t starve yourself. Take your vitamins. Etc.)

1 lb. of body fat = 3500 calories
Calories stored = calories eaten - calories burned
Every day, I eat X calories
Every day, I burn ~2500 calories

If X > 2500, you will gain weight at (X-2500)/3500 pounds per day. If X < 2500, you will lose weight at (2500-X)/3500 pounds per day.

Thus, if you eat 500 calories less than you burn every day, you will lose one pound per week.

Key insight: this is not difficult! For example, a strawberry milkshake from In-n-Out is 700 calories. A 6 oz. frozen yogurt with strawberries and mangos from Fraiche is 200 calories. That’s 500 calories saved right there!


Sounds great! How do I deal with this on a day-to-day basis?

The Hacker’s Diet (Practice)

My mother once told me “Chad, be very careful with drugs and alcohol. You have an obsessive personality.” She was absolutely right about the obsessive personality; fortunately, I’ve learned to channel my obsessions productively. (Although I did spend a year and hundreds of dollars on Travian…)

Here’s how calorie-counting with Lose It! works in practice:

  1. Keep track of everything you eat. This is pretty easy because their database contains most common foods. If it’s not in the database, just enter it yourself. Record it right before or after you eat so you don’t forget.
  2. Estimate your daily caloric burn. There are standard estimation formulae, but the exact amount doesn’t matter a great deal. If you are losing weight faster than you expected, increase your burn. If you are losing weight slower than you expected, decrease your burn. I started at 2500 calories/day, but shortly realized my actual burn was 2300 calories/day.
  3. Stay within your daily calorie budget! Treat it as a hard limit so that, if you screw up and eat a Double Double and Shake (1400 calories total) for lunch, you’ll be very sad at dinner when you can’t eat anything else. :( You won’t make that mistake again. *cough*
  4. Drink water. Take vitamins. Sleep. Take care of yourself if you get sick.
  5. Weigh yourself every day. Watch the mostly-linear progress!

That’s all there is to it! Time + calorie deficit = easy weight loss!

Really? Surely there’s more to it…

Unexpected Side Effects

  1. The first couple weeks after I reduced my caloric intake to ~1800, I got hungry. Then tired. REALLY TIRED. I started sleeping 10 hours a night. It turns out that your body is good at noticing “Hey, where’d the energy go? Time to slow the engine down.” I suspect this is the part where most people quit, especially if they don’t see immediate progress. Remember: this effect is annoying, but temporary. Your body will adjust to the reduced intake and before you know it you’ll feel great again.
  2. My headaches are GONE! I used to get very frequent headaches related to low blood sugar. Maybe burning fat means I have a more even supply of energy through the day? Maybe eating less means my blood sugar doesn’t spike? Who knows, but I’ll take it!
  3. Body fat is an inert material. For years, it quietly stores all kinds of chemicals and toxins. Burning fat means those chemicals go into your bloodstream. Some of those chemicals reek. Thus, you will randomly smell like holy hell for a week or so. You can’t predict when either. I thought John Walker was exaggerating… but it’s true:

    As your body chemistry adjusts, other curious things may happen. One day, trapped in a tedious meeting, I began to emit an odor evocative of a roadkill skunk marinated in ratpiss. My esteemed colleagues were either too polite to remark upon this phenomenon, or (more likely) unsure of the culprit, so I managed to escape to the open air unfingered as the malodorous miscreant. This situation persisted for about two weeks, after which it disappeared for good as suddenly as its onset.

  4. Optimizing for fullness per calorie has unexpected effects. Pizza is actually low-calorie when you consider that two slices of pepperoni is only 600 calories and filling. Fruit is also great: 100 calories for a pear.
  5. Alcohol is full of calories. 80 for a shot of whiskey. :x Turns out I’d rather eat some bread than have a beer.
  6. It’s way too easy to blow your budget on soda and juice. Switch to diet soda, iced tea, black coffee, and water. Liquid calories aren’t worth it.
  7. Speaking of, caffeine is awesome. Suppresses appetite and gives you energy.
  8. Body weight is noisy. On any given day, you may be 4 pounds heavier or lighter than the day before. (You can try this at home: drink two bottles of water before weighing yourself.) Some weeks, it will look like you’ve made no progress. It’s infuriating, but hang in there. In the end, your weight graph will be linear.
  9. When it comes to nutrition, everyone’s an expert. “Are you exercising?” No. “Are you eating healthy food?” Do pizza, burritos, and frozen White Castle count? Dieting is hard enough by itself. Actively avoid being too ambitious. It’s much easier to cut calories if you can still eat things you love. Worry about the low-order bits after you hit your target weight.
  10. I used to love the feeling of a full stomach. Now it’s unpleasant. I’ve finally defeated that post-great-depression “EAT EVERYTHING ON YOUR PLATE OR YOU’RE GROUNDED!” instinct.

Getting Through Rough Days

Let’s face it. Some days you’ll screw up and eat too much for breakfast or lunch. At 11:00 p.m. you can’t sleep because you’re too hungry. How do you take the edge off without blowing your calorie budget?

  • Tomatoes. 35 calories PER! If you like ’em, chow down.
  • Cantaloupe. 35 calories per 1/8 melon.
  • Hot chicken broth in a mug. Warm, tasty, and 50 calories.
  • Strawberries. 8 calories per delicious berry!
  • Low-calorie yogurt. 60 calories.
  • String cheese. 70 calories.
  • Pickles. ZERO.
  • Water. ZERO. Somehow, drinking water can make you less hungry!
  • Also, if you still want crackers or cookies, 100 calorie packs are pretty common these days.

And finally, my secret weapon… Trader Joe’s Whole Wheat Bread. I can’t remember its exact name, but it comes in half-rounds and has three ingredients: whole wheat, water, salt. 200 calories, 16g of protein and 16g of fiber per EXTREMELY FILLING slice. You can eat this stuff until your jaw hurts. It’s epic. However, keep in mind that 16g of fiber is a ton. Stay near a bathroom.


What About Exercise?

Remember the basic equation:

Calories stored = Calories eaten - Calories burned

You can lose weight with exercise, but it’s harder than you’d think. Exercising tends to make me hungry, causing me to eat more than I would normally. Plus, it takes a lot of exercise to burn off a significant number of calories. If you vigorously lifted weights for an hour, you’d only burn ~400 calories, less than a single cheeseburger! You’d have to keep that up every single day without increasing your diet to lose a less than a pound per week. I decided it’s easier to simply eat less.

Note that I’m not saying that exercise is not valuable. Exercise has great health, happiness, and life extension benefits. I just don’t think it’s an efficient way for me to lose weight.

What Next?

What next? I think I’m going to try to drive my weight down a bit further and then replace the pounds of fat lost with muscle. Or maybe I’ll get myself to floss every day. We’ll see!

I always thought weight loss was hard because I’d witnessed people throw themselves at it hardcore and then fail just as hard. In contrast, I chose an easy, long-term, data-driven plan and stuck with it. Small changes over a long time make a big difference.

25 thoughts on “How I Lost 20 Pounds in 20 Weeks With My iPhone (or: Data is King)”

  1. Great article!

    I have been using loseIt! and have lost 37 lbs. so far! (about 10lbs. a months or 2.5 per week).

    I have to loose a total of 100 lbs. so I still have a long way to go but so far its been fairly painless and even fun.

    My wife has lost about 20 lbs. as well!

    The iPhone might end up saving my life.

    Also – A really good food is cucumber slices with rice vinegar and a touch of toasted sesame oil. Almost not calories and delicious! ( I also add some siracha garlic-chili sauce)

  2. Fantastic, Raul! That cucumber slices suggestion is great. My mom used to make something like that when I was a kid, so I’m sure I’d love it.

    When I first got the iPhone I thought it was too expensive, but the weight loss was worth it!

  3. Nice post, Chad…lots of great points and suggestions. “Delicious downtown Palo Alto” haha agreed!

    I also have lost quite a bit of weight recently (60lbs over 6 mos) and have a couple of very lo-tech suggestions that worked for me:

    – Use small plates at home! I switched to 5″ diameter round plates at home from 10″ and learned that just finishing one plate of food, regardless of actual amount, is satisfying.

    – Always leave half of whatever you order when you eat out! I do this by default now, even if I want more. If I’m with my wife, we just split a single item for the same net effect.

    – Prep a bunch of salad toppings on Sunday to use throughout the week. Make it super convenient to eat a low calorie salad. I store 10 items in a plastic divided container.

    I haven’t really changed *what* I eat at all…still put bacon, blue cheese, and ranch on my salad. But I’ve cut caloric intake tremendously and without any exercise have seen results. My next step should be one you recommend, with more data behind it, but this was a start. Cheers!

  4. Chad – you look great! Keep up the good work, and continue to be a positive role model and influence on those working around you. Exercise isn’t just to lose weight, although you underestimate its impact. Exercise burns calories while you’re doing it… and beyond. In effect, you are creating bigger muscle “furnaces” that continue to burn more fuel (fat) throughout the day. You are changing the formula you refer to by increasing your metabolism and thus the caloric burn. I’m on the same quest as you, though I have much further to go. I look forward to all of us reaching the right balance of fitness and fun.

  5. Thanks for the comments! I realize now that I was a too harsh on exercise. It definitely has great benefits, and I’m looking forward to transitioning to maintaining my weight while increasing exercise!

    Good luck!

    Regarding Greg’s salad, I always loved this one guy’s diet plan:

    1) Eat food.
    2) Not too much.
    3) Mostly plants.

  6. very nice article : very inspirational :)
    really motivated me to get back on track.
    i have this app on my iTouch &. im really gonna get into using it again ….

  7. Your story is so similar to mine, I thought I was reading about myself. I also used Lose It, and using it daily is just a natural habit for me now. I lost as much weight as you did (even a bit more, but it’s your post so I won’t go there) and I now weigh what I did in high school. Good work man!

  8. Great article & well done on keeping to the plan. I’ve always been impressed by how well weightwatchers have simplified this approach so that anyone who can count to 30 can do it (they have a daily points budget depending on your weight, each food ‘costs’ a number of points and you can get ‘bonus points’ for exercise). It also makes it clear to people what the effect of their choice of food is (e.g. 1 chocolate bar may have the same amount of points as a whole main course). As a computer/maths type I’m more interested in exact figures & graphs myself though and your approach sounds great.

    Just a couple more low calorie snacks:
    – raw carrot (can be quite tasty and something like 15 calories/carrot)
    – an orange (about 40 calories and quite filling – also time consuming to peel & eat!)

  9. Congrats on your success! This summer I also read the Hackers Diet and downloaded Fit Now for my iPhone. Small planet. I lost 10lbs in 8b weeks. My wife and sister did even better. For some reason the thought counting calories was obsessive & crazy, but not anymore. ;-)

  10. Miso Soup is also a great low-cal, very filling food. In fact, be careful because it is extremely filling and only 15 calories per tablespoon of miso paste.

  11. I’ve been meaning to write this exact blog post but have been too busy. Now I don’t have to. My wife and I did exactly what you did. However, we also used EA Sports Active for the Wii, which is a great way to get a little exercise without boring you to tears. Of course, it also helps that we did it together so we weren’t undermining each other’s progress. She’s lost nearly 45 and I’ve lost 32 since June.

    Congratulations on your success too, and also for sharing this with everyone.

    And FYI – salsa and corn chips is a good low-calorie snack too. I’d be sunk without that. :)

  12. Well done, but this is based on a flawed understanding of thermo, specifically found in the ‘hacker’s diet’. A sedentary person with a small frame will not burn ~2500 calories per day, it could be as little as ~1000, so many people will still gain weight eating 2500 calories until fat equilibrium is achieved, which could equal quite a bit of fat.

  13. The only point I would argue with here (I had similar results last year, and have kept it off for a year now) is putting off exercise. You do need to build muscle mass as well as lose body fat, primarily because a year from now if you look at the numbers again you will see that your basal metabolic rate (how much your body consumes while doing nothing) and activity level no longer consume the 2300 kcal you are seeing now.

    As has been pointed out, exercise burns a lot more calories than what you’ll see on the heart rate monitor calculator (or online charts); the main energy burn is (1) from rebuilding the muscles after the workout, and (2) from maintaining the muscular frame in everyday life. The second is what increases that basal metabolic rate, allowing you to consume far more calories in the day without gaining weight.

    But, seriously: take it one step at a time, as you’ve said. If exercise is really too much to fit in right now, then start with diet. Don’t start off trying to track every nutrient under the sun; focus on calories first (and you’ll find that foods which fill you up and keep you full are generally more nutritious in any case). On the other hand, once you’ve taken that first step, don’t be afraid to take the next. Adding in some exercise (get out and walk around a park, or whatever) is easier than most people think; you just need to commit to doing it and get it done.

    On tools, I can’t vouch for Lose It!, but have had a lot of success with CalorieKing’s product. I don’t think they have a mobile version of it, and the interface is clunky, but the database is absolutely rock-solid, containing just about everything we run across in the grocery store or at fast food restaurants. I also really like how when I wanted to start tracking, for instance, sodium intake, I could easily go back through the last several months of history and see how I had been doing before really paying attention to it.

  14. @Name (required)

    The different calorific equilibrium point is addressed in the OP:
    “Estimate your daily caloric burn. There are standard estimation formulae, but the exact amount doesn’t matter a great deal. If you are losing weight faster than you expected, increase your burn. If you are losing weight slower than you expected, decrease your burn.”

  15. I started out with LoseIt! based on your post, and reading the Hacker’s Diet just 2 weeks ago. What John writes absolutely clicked in my engineer’s brain.

    But – as you pointed out, data IS king … and I found LoseIt’s database to be lacking in a lot of instances. So I opted instead to pay a couple bucks for LiveStrong which has a phenomenally more comprehensive database – and this makes the tracking even easier. Although their UI has some bugs and takes some futzing from time to time to get it to take your data.

    My goal in LoseIt (and the LiveStrong app works largely the same way) was to lose 1.5lbs per week to lose 32 pounds. So far, over two weeks, I’ve lost 3.8 so I’m over by about 0.4 lbs per week. I’m going to give it one more week at the same calorie goal and see what the trend is, and if I’m still over by a bit — then I will adjust my caloric intake per day by ~ +100 calories or so to adjust.

    Over the entire two weeks – I’ve eaten whatever I wanted! Wendy’s Spicy Chicken Sandwich? No problem. Coupla slices of a Tombstone pizza? No problem. French toast? No problem! This is great, because as I enter foods into the app in real-time throughout the day … I start to get an idea of what I can (or can’t) have for dinner that evening, and adjust accordingly.

    Here are a couple of things that have helped me out quite a bit so far:

    1) Go to the grocery store, get some frozen dinners (I like Marie Callendar’s) in varying caloric amounts of 350 – 400 – 500 – 600 – 700. This way, if you have roughly ~580 calories left at the end of the day … you probably have a dinner on hand that hits that amount or close to it. I also suggest getting pre-made lunch sandwich kits (I like Deli Creations) in varying caloric amounts as well.

    2) Buy a couple bags of “fun size” candy bars – snickers, butterfinger, whatever – to keep on hand. These are all around ~50-100 calories each … and can really knock the edge off your appetite if you’re feeling hungry. If I’m 100 calories short on the day at 9pm, I’ll simply eat a fun-size butterfinger to make sure I hit my caloric goal as closely as possible. Added bonus is I’m not feeling hungry at all when I go to bed either.

    3) For while I am losing weight, I will opt more for “chain” restaurants over some of my local (non-chain) favorites … simply because there’s a higher likelihood of having accurate calorie data available for their food items. While there’s a local steakhouse that I love – it would simply be better for me to substitute Outback in instead in order to have more accurate data.

    4) Learn to like fish! A 6oz haddock or flounder fillet, is about 150 calories! That opens up a lot of other calories for dinner for things like a glass of wine, or maybe some dessert.

    5) Stock up on some Omaha steaks (and other meats from them) for cooking at home – they’re sold in specific “ounces” sizes which makes tracking calories super easy.

    6) Get a food scale for at home to weigh some of the items you’re cooking. Last night, I grilled a couple of haddock filets that I got from the grocery store. They were different sizes, so I just dropped each on the scale before cooking – just to know how many ounces each (10oz, 6oz) was. From there, calculating the calories in LiveStrong is a no-brainer.

    7) Sodas are mostly gone from my life, now – but not out of any sense of “I can never have a soda again” … it’s simply not worth the calories most days. But, if I really want one – or if it’s all that’s available – it’s really no big deal.

    8) Random throughout-the-day snacking is effectively gone from my life (for good). It’s amazing how much more accountable you feel when you have to track *everything* that you shove in your word-hole.

    Unexpected side-effects so far:

    1) I’m eating on a much more regular schedule now! Before, my “feeding times” were kind of all over the map. No breakfast … maybe lunch at 11 or 2, possibly dinner at 6 or maybe at 9. All over. Now, I seem to have mentally snapped into a pretty sensible noon for lunch, 6pm for dinner schedule without even consciously trying.

    2) I’m not really all that tired. I wouldn’t say my energy level has gone up or down as a result of this. Hopefully that’s a good thing.

    I hope to revisit this thread in April and proudly announce that I’ve lost all 32 pounds from my goal!

  16. Congrats on the weight loss!

    This is wrong:
    “Body fat is an inert material. For years, it quietly stores all kinds of chemicals and toxins. Burning fat means those chemicals go into your bloodstream. Some of those chemicals reek.”

    Hacker’s diet isn’t totally right either … it’s right like Newton was right in that it explains things, but it doesn’t explain them very deeply. For example, why do so many of us have screwed up eat watches?

    Read this book. It’s a geek’s dream. Seriously, read it.

  17. Awesome article. Sounds just like my journey. I’m 5’3″ and my weight had gradually climbed to 195 lbs (I was 140 lbs in high school). I started working to lose weight about two weeks prior to my wedding. 20 weeks later, I’m at 171, 24 lbs less than where I started. I know that the BMR calculators are my best friends, since your rate changes with your weight and your level of activity. I have recently started to implement exercise as well. It wasn’t easy, but it sure was worth the effort. I look at my wedding photos (I hate them by the way), and I’m sometimes fascinated with how far I’ve come since then. I still have some ways to go. I know I’m probably not going to get back to my high school weight, but I plan to stick to what I’m doing now and see what happens…

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