Why We Get Fat Summary

What if the very foundation of what we've been told about weight gain is wrong? It's not simply eating more and moving less—it's what we eat that matters most.

1. Caloric Intake Misconception

Many people believe that eating more calories than one burns leads to weight gain. This assumption treats the body like a simple math equation: energy in versus energy out. However, this logic overlooks the complexities of how the body uses and stores energy.

The truth is, some individuals eat sparsely and remain overweight, while others indulge and stay lean. For example, indigenous groups in poverty, subsisting on minimal nutrition, often displayed obesity among adults but malnourishment among children. This contradicts the idea that mere overeating causes fat accumulation.

Additionally, the caloric model can't explain why certain people, who share the same lifestyle, experience very different outcomes in weight gain. These inconsistencies highlight a gap in traditional thinking about obesity causes.

Examples

• Indigenous American mothers were obese despite limited food availability.
• Overweight individuals often eat less than thin counterparts, with no weight loss.
• People in high activity jobs, such as laborers, have also shown obesity trends.

2. Fat Isn't the Villain

The 20th century linked fats with heart disease, ushering in the belief that eating fat made people fat. This idea dominated dietary approaches for decades. Yet, despite cutting fats, obesity rates only increased.

Research from the 1980s showed that stigmatized fats weren’t responsible for the massive uptick in weight or related conditions. Diets low in fat, ironically, led people to eat high-carb foods, like bread and pasta, intensifying fat storage due to insulin spikes triggered by these carbs.

Moreover, arthropological studies of isolated hunter-gatherer societies revealed that diets heavy in fatty meat did not result in health or weight issues until refined carbohydrates were introduced.

Examples

• Low-fat diets from the 1950s-1970s coincided with rising obesity cases.
• Evidence from societies like the Inuit showed little obesity on high-fat diets.
• Cutting fat led to higher carb consumption, correlating with weight gain.

3. Exercise Isn't Enough

Common advice like "just exercise more" isn’t as effective as it sounds. Physical activity doesn’t override the influential role of diet, especially high-carb consumption. The more we exercise, the hungrier we become, often leading us to eat more.

This principle is seen in adolescents during growth spurts—they become lethargic because their bodies channel energy into growing. Similarly, people with growing fat cells may feel tired and require more calories without being “lazy” or lacking effort.

Historical examples back this up. Mexican laborers in grueling jobs still had obesity rates as high as 40%, despite low caloric diets and extreme physical activity. This underscores that exercise alone doesn't solve the problem.

Examples

• Studies of growth spurts: energy goes toward growth, not physical activity.
• Mexican workers showed obesity despite hard labor and minimal calories.
• People exercising to lose weight often gain appetite instead.

4. Insulin and Carbs: The Real Culprits

Insulin has a primary role in how the body processes carbohydrates, fats, and proteins. When we consume carbs, insulin rises to process sugar in our bloodstream. This leads to energy being stored as fat if it isn’t immediately burned.

Carb-heavy foods, like bread, rice, and sweets, flood our bodies with glucose, spiking insulin levels. These high levels promote fat storage while simultaneously reducing the body’s ability to break down existing fat cells.

Studies confirm that reducing carbs correlates with effective weight control. By limiting insulin disruptions, the body not only decreases fat storage but also starts using stored fat as energy, aiding weight loss.

Examples

• Carbohydrate-heavy diets lead to consistent fat gain in modern societies.
• High insulin maintains fat accumulation, even while reducing calorie intake.
• Removing carbs forces stored fat reserves to provide energy.

5. Evolution Didn't Prepare Us for Modern Carbs

For millions of years, human diets were low in carbohydrates, consisting mainly of meat, fish, and occasional fibrous plants. High-carb foods like bread, potatoes, and sugar emerged only in recent human history, leaving our biology poorly adapted to process them.

Indigenous hunter-gatherer diets studied by scientists are virtually carb-free. Despite consuming large quantities of fat and protein, these communities showed no signs of typical Western diseases such as diabetes or heart conditions.

Modern processed foods, full of sugar and refined carbohydrates, overwhelm our bodies. These quick-burning carbs disrupt our metabolism, triggering excessive insulin release and, over time, developing resistance to its effects.

Examples

• The agricultural revolution introduced grains, altering human diets.
• Isolated tribes with no carb consumption reported zero obesity.
• Refined sugar introduced in the 19th century linked with widespread weight gain.

6. The Health Risks of Carbs

Carbohydrates aren't just tied to obesity—they contribute to a range of metabolic and chronic diseases. Long-term carb-heavy diets overload the insulin system and cause persistent inflammation.

Immigrant groups transitioning to Western diets showed a spike in diabetes and cancer rates. For example, breast cancer is rare among native Japanese women, but rates increase among descendants living in Western countries.

Cultural shifts to carbohydrate-rich diets correlate with a surge in cardiovascular issues, diabetes, and even Alzheimer's disease, often labeled "Type 3 diabetes" due to its connection with insulin resistance.

Examples

• Native populations developed diabetes when exposed to sugars and flour.
• Breast cancer rates mirrored Western values after diet changes.
• Alzheimer's links to insulin resistance prove carb-related sickness.

7. The Problem with Low-Calorie Dieting

Cutting calories may provide brief results, but it damages the body in other ways. Nutrient deficiencies emerge when food intake is limited, causing fatigue, muscle loss, and poor health over time.

The so-called yo-yo diet effect further discourages sustained progress, as lost weight often returns when regular eating resumes. In one eight-year study of 20,000 women eating fewer calories each day, participants lost minimal weight while some gained belly fat.

Repeated calorie restriction also slows metabolism. This resistance, paired with dietary exhaustion, leaves many dieting individuals worse off than when they started.

Examples

• 20,000-women study showed almost no weight loss after 8 years of dieting.
• Low-calorie diets strip essential nutrients, weakening the body.
• Yo-yo dieting leads to rapid rebound weight gain each time.

8. Age and Genetics Matter Too

Age naturally affects weight, as insulin resistance increases over time. The more we consume high-carb diets during our lifetime, the worse our body processes sugar later on. Consequently, older individuals struggle proportionally more with weight gain.

Genetics also play an essential role. Some people are predisposed to store energy as fat, while others burn excess calories easily. These natural tendencies explain why some gain weight with minimal food while others remain slim on high-carb diets.

Eating large amounts of carbohydrates accelerates insulin resistance, turning small dietary habits into fat-storing cycles as people age.

Examples

• Older adults show higher insulin resistance than younger groups.
• Weight gain can be genetic, explaining individual differences.
• Lifelong carb-heavy diets gradually worsen resistance.

9. Low-Carb Diets Work, Despite Popular Opinion

Low-carb diets are often criticized, yet they align most effectively with how our bodies are designed to function. High-fat, low-carb regimens encourage the breakdown of existing fat without triggering insulin spikes.

Anthropological data supports this: societies with low-carb, high-protein diets showed no obesity or “Western diseases” until encountering flour, rice, and sugar. These findings challenge the mainstream belief that fat-rich diets are unhealthy.

By replacing carbs with nutrient-dense vegetables and healthy fats, one can maintain energy, combat obesity, and even reverse chronic conditions associated with long-term carb consumption.

Examples

• Isolated groups experienced obesity only after adopting refined carbs.
• Meat-heavy diets supported excellent health in indigenous populations.
• Swapping carbs for fats led to weight loss with steady nutrient intake.

Takeaways

1. Reduce or eliminate processed carbohydrates, focusing instead on lean meats, fish, and fiber-rich vegetables to maintain insulin balance.
2. Avoid falling into the calorie-counting trap; prioritize nutrient density and stabilize your metabolism with healthier, whole foods.
3. Monitor personal sensitivities to carbohydrates; if you're prone to weight gain, try a low-carb approach tailored to your needs.