Japanese People Move to America and Their Obesity Risk Skyrockets 400%. The Reason Isn’t Food, It’s This

Weight loss advice floods our feeds daily, yet 70% of Americans remain overweight or obese.

Dr. Jason Fung, founder of the intermittent fasting movement, argues the problem isn’t willpower—it’s the advice itself.

His new book, The Hunger Code, reveals why traditional calorie counting delivers a staggering 99.6% failure rate.

What follows are three golden rules that challenge everything you’ve been told about losing weight.

Why Calorie Counting Fails Almost Everyone

Decades of “eat less, move more” messaging has created a self-perpetuating myth, according to Dr. Fung. People assume the advice must work simply because experts keep repeating it.

How do you get a 99.7% failure rate without the advice being bad?

Studies examining large populations show calorie restriction rarely produces lasting weight loss. Yet the fitness industry, medical professionals, and media continue promoting this approach.

Dr. Fung identifies two possible explanations: either the advice is flawed, or people are inherently weak. He firmly believes it’s the former.

Is it really their fault each one individually decided to gain this weight that they didn’t want? I don’t think so.

The Three Why’s: Getting Beyond Surface Solutions

Dr. Fung uses a logical framework called “the three whys” to expose shallow thinking about weight gain. Asking “why” only once produces superficial answers that don’t address root causes.

First why: Why am I gaining weight? Because calories in exceed calories out.

Second why: Why is calorie intake greater than output? Because you’re hungry.

Third why: Why are you hungry? This is where meaningful solutions emerge.

Cutting calories while ignoring hunger creates constant internal warfare. You eat less, but you’re hungrier, forcing daily battles with your own biology.

Addressing hunger directly, however, naturally reduces food intake without struggle. This principle explains why medications like Ozempic work—they target hunger, not calories.

Your Body Fat Thermostat: The Missing Piece

Just like room temperature stays constant through heating and cooling systems, body fat is regulated by internal mechanisms. Wild animals never become morbidly obese because their bodies maintain optimal fat levels for survival.

When this “body fat thermostat” rises, it signals your body to eat more through increased hunger. When it lowers, hunger diminishes naturally until weight normalizes.

The question is, why has that body fat thermostat, which is the one that controls how much body fat you carry, gone up? And the answer is hormones.

Hormones like insulin, cortisol, GLP-1, and leptin all influence this thermostat. When you simply cut calories without addressing these hormonal signals, your metabolic rate drops to compensate.

Sleep deprivation raises cortisol, which elevates the body fat setpoint, triggering increased hunger. The solution isn’t eating less—it’s sleeping more.

Exercise: Why It’s Not About Burning Calories

Exercise stimulates the sympathetic nervous system, which temporarily suppresses appetite during activity. This acute hunger reduction can support weight loss, but not through calorie expenditure.

Studies show that beyond approximately 2,500 calories of activity, total energy expenditure plateaus. Bodies become more efficient, reducing metabolic rate to compensate for increased movement.

Moderate exercise—30 to 45 minutes daily—burns only about 150-200 calories, roughly equivalent to two slices of bread. Post-exercise hunger often rebounds, negating any caloric deficit.

Exercise remains crucial for health, but expecting it to drive weight loss through calorie burn sets up disappointment.

Golden Rule #1: Avoid Ultraprocessed Foods

Ultraprocessed foods represent approximately 70% of American diets, yet only 20% in countries like Italy where obesity rates remain lower despite passionate food cultures.

Food companies engineer products to maximize “hedonic hunger”—eating for pleasure rather than physical need—while minimizing satiety signals. This creates foods you can consume endlessly without feeling full.

These products reduce protein and fat, both of which trigger satiety hormones like GLP-1 and cholecystokinin. Without these signals, consumption continues far beyond nutritional requirements.

If you want to sell a lot of food, you want sort of all these chemicals, all these textures, all these things, but also make it very easy to eat and create no satiety.

Food Addiction Is Real

Research now confirms that certain ultraprocessed foods trigger genuine addiction in 20-30% of overweight individuals, according to the Yale Food Addiction Score.

People report addiction to ice cream, chocolate, and pizza—never to eggplant, beef, or sushi. Processing transforms natural ingredients into addictive substances, just as tobacco becomes cigarettes and poppies become morphine.

Addiction requires treatment through abstinence and support, not moderation and willpower. Telling food addicts to “just eat less” is as ineffective as advising alcoholics to drink moderately.

Avoid “Naked Carbs”

Naked carbs—refined carbohydrates eaten alone—get absorbed rapidly, spiking blood glucose and insulin. This quick absorption pattern mirrors the addictive hit from smoking nicotine or injecting heroin.

Mixed meals slow digestion significantly. Eating vegetables and protein before carbohydrates reduces insulin levels by 20-30% compared to eating carbs first.

Food order matters because stomach contents mix together before releasing into the small intestine. Starting with vegetables means each release contains fiber, protein, and small amounts of carbohydrate—not pure glucose.

Golden Rule #2: Don’t Eat All the Time

Fasting isn’t radical—the word “breakfast” literally means breaking your fast. Extended periods without food represent normal human eating patterns for millennia.

Contrary to expectations, fasting decreases hunger rather than increasing it. When you stop eating, your body adapts to accessing stored body fat for energy.

People who start fasting, they notice their appetite has just gone way down.

This adaptation becomes habitual. Habits require zero willpower—they become automatic behaviors that deliver ongoing benefits without constant decision-making.

Fasting addresses all three types of hunger:

• Homeostatic hunger: Physical need for nutrients decreases as fat-burning improves
• Hedonic hunger: Pleasure-seeking eating gets interrupted by designated non-eating periods
• Conditioned hunger: Habitual snacking patterns break when fasting becomes routine

For beginners, skipping breakfast creates the easiest fasting window, though dinner might be optimal for metabolic benefits.

Golden Rule #3: Fix Your Environment and Community

Individual willpower matters far less than environmental factors. Japanese people living in Japan have extremely low obesity rates, but those same individuals transplanted to San Francisco see obesity risk skyrocket within generations.

When someone’s best friend becomes obese, their own obesity risk increases 171%. Military families moved to high-obesity areas immediately experience higher obesity rates themselves.

Social modeling and conditioning shape eating behaviors more powerfully than personal determination. Communities normalize portion sizes, food choices, snacking frequency, and attitudes toward fasting.

Community is the most important thing because everybody’s heard about calories. Everybody’s heard about diets. It’s not about the diet. If you think it’s about the food, you’ve already lost.

States like Colorado, with outdoor-focused cultures, and California, emphasizing fresh local foods, demonstrate significantly lower obesity rates than the national average.

Mindset Drives Behavior Change

Viewing sugar as poison rather than forbidden pleasure eliminates internal conflict. When Dr. Fung shifted from “sugar is sweet but bad” to “sugar is toxic,” consumption dropped 75-80% effortlessly.

Similarly, framing exercise as punishment breeds resistance, while viewing it as enjoyable activity encourages consistency. Mindset changes don’t require Herculean effort—just repeated reinforcement.

Reading ingredient lists with the belief that chemical additives are harmful naturally reduces ultraprocessed food purchases. The shift from “I want it but can’t have it” to “I don’t want it” removes deprivation.

Why Natural Fats Support Weight Loss

For decades, mainstream nutrition demonized fats, labeling nuts, avocados, olive oil, and salmon as heart attack risks. Research eventually revealed that eating these foods actually reduces cardiovascular events.

Any natural fat—butter, coconut oil, animal fats from quality meat—can be consumed generously without concern. These fats trigger satiety hormones and slow carbohydrate absorption.

Comparing 800 calories of steak and eggs to 800 calories of a frappuccino illustrates this perfectly. The steak and eggs provide sustained energy until the next meal. The frappuccino gets stored immediately as fat, leaving you hungry within the hour.

Same calories, radically different hormonal responses, completely different outcomes.

The Oldest Advice Still Works Best

Ask any grandmother for weight loss advice and you’ll hear: don’t eat all the time, and avoid junk food. This wisdom has survived thousands of years—it’s even mentioned in biblical texts.

Calorie counting emerged only 50 years ago, coinciding with rising obesity rates. Ancient fasting practices have proven their worth across millennia and diverse cultures.

The Lindy Effect suggests that advice lasting thousands of years will likely remain relevant, precisely because it works. Modern “scientific” approaches obsessed with calories have failed spectacularly by comparison.

Weight loss isn’t a simple calorie equation. It’s a complex interplay of hormones, processing, digestion, absorption, environment, habits, mindsets, sleep, stress, and community. Reducing this complexity to “eat fewer calories” is both lazy and ineffective.

Find your community. Change your environment. Address your specific hunger type—whether homeostatic, hedonic, or conditioned. Stop counting calories and start changing behaviors.