Book SummaryThe Hacker's Diet, by John Walker

1-Page Summary1-Page Book Summary of The Hacker's Diet

How do you lose weight? Eat less than you’re burning each day.

It's simple. But simple doesn’t mean easy. Like anything else in life, successfully losing weight requires:

• A fixation on the goal you want to achieve
• An understanding of what’s required to achieve the goal
• Developing a rational plan to meet your goal
• Carrying out the plan
• Willpower and a high tolerance for pain

Calories In/Calories Out

The way to lose weight is to eat fewer calories than you’re burning each day.

Everyone has a different daily calorie requirement based on height, weight, and activity level. Very roughly, the average man burns around 2000 calories, and the average woman around 1500 calories. Determine yours with this calculator.

A pound of fat contains about 3500 calories. Losing a pound of fat requires you to burn 3500 more calories than you eat. There’s no way around this. Fad dieting techniques like keto, paleo, intermittent fasting, etc. are all merely different ways of restricting your calorie intake.

Likewise, eating an extra 250 calories a day causes you to gain a pound in 2 weeks. Or 26 pounds a year. And this just requires one more helping at dinner, one beverage per day.

For purposes of weight loss, you could eat 1500 calories of butter a day and still lose weight. It’s not what you eat, it’s how much of it.

The Eat Watch

Imagine that you had a watch that told you when to eat. When it flashed Eat, you would eat. When you reached your calorie limit for the meal or the day, the watch would stop flashing, and you’d stop eating.

People who have been skinny their entire lives have perfectly tuned Eat Watches. When they eat over their caloric requirement for the meal, they simply stop eating. Eating past this point becomes unbearably uncomfortable.

People who gain weight easily have broken Eat Watches. Cutting calories is painful; eating excess calories is easy. It might even be easy for you to keep eating past the point of discomfort.

But this doesn’t mean you’re doomed for life. Many of us are born with bad vision, but you can get glasses to correct your problem. If you have a broken Eat watch, you can build your own artificial one, by tracking your weight and calories.

Tracking Weight

If you’ve ever tried to lose weight and measure your body, the path your body takes is startling.

• When you first start dieting, you seem to lose 5 pounds in 2 days. Wow! What progress!
• Then it quickly slows to a trickle. This is the plateau of misery.
• You get antsy and frustrated, so you have a cheat meal. You stand back on the scale, and you weigh 4 pounds more. My god! All your progress is lost!
• As you weigh yourself through the days, your spirits rise and fall with your readings. Plateaus are crushing (you’re enduring...

The Hacker's Diet Summary 1: How to Lose Weight

There’s a story about financial traders on Wall Street. A novice asks a guru, “How do you make money in the market?”

The guru responds, “It’s simple: buy low, sell high.”

The beginner replies, “How can I learn to do that?”

The guru responds, “Ah — that takes a lifetime.”

Simple doesn’t mean easy.

How do you lose weight? It’s simple. Eat fewer calories than you’re burning each day. But simple doesn’t mean easy.

What weight loss really requires is:

• A fixation on the goal you want to achieve
• An understanding of what’s required to achieve the goal
• Developing a rational plan to meet your goal
• Carrying out the plan
• Willpower and a high tolerance for pain

This is what’s needed in any of life’s hurdles. This is precisely what losing weight achieves.

The author is John Walker, founder of software company Autodesk. He spent most of his life fat, before figuring out how the body and weight loss works. Then, in less than a year, he lost 60 pounds and kept it off forever.

This book is an engineer’s approach to weight loss, described in terms of control systems, feedback loops, measurement noise reduction, and practical problem-solving.

In the first 4...

The Hacker's Diet Summary 2: Eating’s Feedback Loops

Wouldn’t it be great to have a watch that tells you when to eat and when to stop? When it says EAT, you can eat. It’d monitor what you’re eating, track calories for you. Then when it figures out you’ve had enough calories for the meal to keep your weight, it says STOP, and you stop eating. The Eat Watch would be smart enough to keep you at your daily calorie limit for your ideal weight.

Some people are born with a natural, built-in eat watch that works perfectly. Let’s call this type of person Skinny Stable Sam. They eat only the amount needed to maintain their thin bodies, for their entire life. If they eat less than what they burn, they get hungry and they eat. If they overeat in a meal, they feel uncomfortable and take longer to get hungry again, plus they eat less in a later meal. Their point of discomfort and satiety is set precisely at...

The Hacker's Diet Summary 3: Measuring Weight

Tracking calories is critical — it’s easy to overeat, and having a strict boundary will make it less likely for you to eat past your goal. And if you perfectly measure your calorie intake, then it should correspond well with your weight loss.

But how many calories you’re eating isn’t your final goal — your weight is. Your weight keeps you honest — if you’re not losing pounds as quickly as you think you should be, then you’re probably eating more than you think, or you burn fewer calories than you estimated. Either way, you need to adjust.

If you’re serious about losing weight, you should measure your weight everyday. To do otherwise is to try to drive without looking at the road. Would you drive by looking at the road for 1 second, then covering your eyes for 4 seconds before looking again?

The Typical Weight Loss Path

If you’ve ever tried to lose weight and measure your body, the path your body takes is startling.

• When you first start dieting, you seem to lose 5 pounds in 2 days. Wow! What progress!
• Then it quickly slows to a trickle. This is the plateau of misery.
• You get antsy and frustrated, so you have a cheat meal. You stand back on the scale,...

The Hacker's Diet Summary 4: Planning Meals

Pre-planning meals — how much you eat AND when — gives you a reliable daily calorie intake. If you eat only what you plan to, then you’re guaranteed to achieve your goal. (Again, simply, not necessarily easy).

You would never invest in a company that sets no budgets and whose strategy is “spend whatever we feel like day to day, and hope it’ll work out in the long run.” Not only would this be more likely to fail than methodical planning, there’d be no way to measure actual performance against goals to figure out the problems. “Winging it” in relation to your eating target is the same.

Rigid planning of meals, and adherence to the plan, is the most important strategy in losing weight. You will lose some spontaneity of your eating, but you will be rewarded by weight loss.

Planning meals has these benefits:

• It helps you avoid the in-the-moment temptation to get a plate of seconds.
• It avoids reliance on your internal eat watch, which we already know is broken — without constraints, you will eat far beyond what your body needs for maintenance.
• It avoids unpredictable meals, which leads to unpredictable calorie consumption. If you go to lunch without any...

The Hacker's Diet Summary 5: Starting to Lose Weight

We've now covered all the critical knowledge and tactics needed to lose weight. Now we formally put it together into a feedback loop system that controls your weight:

• Estimate the calories you need.
• Plan your meals to meet your calorie target.
• Log your weight daily.
• Observe the trend of your weight. This gives you the truth of your net calorie balance.
• Adjust your calorie estimate to keep track of your trend.

If you’re losing less weight than you expect, there are only two possibilities. Either you’re burning fewer calories than you expected, or you’re eating more calories than you budgeted, or both. Analyze your situation, and adjust accordingly.

This forms the feedback loop you need to lose weight. By going through multiple iterations of measurement and adjustment, it is simple to reach your goal.

Getting Ready

If you have little knowledge of calorie content of foods, and tracking weight is new to you, it may be wise to spend a couple of weeks just getting used to the actions — monitoring your daily weight and measuring your calorie spend. Once you’ve become...

The Hacker's Diet Summary 6: Perfect Weight Forever

The majority of people who lose weight end up gaining back every pound they lost. You might have gone through a few cycles of this yourself. You might feel hopeless that even if you do lose weight, you will inevitably gain it back — so what’s the point?

The reason people regain weight is that they don’t change their eating behaviors after they lose weight. Meeting their goal, they blissfully return to using their broken eat clock.

Assuming that you were born with a broken eat clock and it’s not possible to develop a working one, keeping your weight for a lifetime requires a lifetime of guidance about how much to eat. Specifically, this means continuing the best practices of what got you here: 1) daily weight tracking and 2) meal planning.

Someone with poor eyesight has to wear corrective lenses to see properly. Without them, she is lost. Likewise, you may have to accept that you have genetically problematic eating controls.

This is the cost of being healthy and avoiding yo-yo weight fluctuations. It’s also the cost of earning valuable freedom — in the foods you eat, your meal schedule, and how much or little you exercise. You can return to eating whatever you...

The Hacker's Diet Summary 7: On Exercise

The most important thing to understand about exercise is that diet control is far more effective at causing weight loss than exercise. For most people, it is much more painful to burn 100 extra calories by jogging than it is to merely avoid 100 calories of food.

But what about gaining muscle? Each additional pound of muscle only burns 6 calories per day. And gaining a pound of muscle is far...

Shortform Exercise: Reflecting on Weight Loss

Think about what you’ve learned from this book and how you’ll approach weight loss now.

What were the most useful concepts about weight loss that you learned from this book?