Keto Diet (ketogenic) is high-fat, very-low-carb eating plan that dominated 2017-2020, promising rapid weight loss through metabolic state called ketosis. Initially medical diet for epilepsy, it became mainstream phenomenon with dedicated products, restaurants adapting menus, and intense online communities before backlash over sustainability and health concerns tempered enthusiasm.

The Science

Keto basics:

• <50g carbs daily (often <20g)
• 70-80% calories from fat
• Moderate protein
• Forces ketosis (burning fat for fuel)
• Originally epilepsy treatment (1920s)

The Explosion (2017-2019)

Mainstream adoption:

• Celebrity endorsements
• Before/after transformations
• “Bacon and butter” diet appeal
• Bread/pasta substitutes booming
• Restaurant keto options

Keto Products

Market response:

• Keto bread, pasta, desserts
• MCT oil, exogenous ketones
• Keto meal delivery
• “Net carbs” labeling
• Billion-dollar industry

The Community

Keto culture:

• r/keto subreddit massive
• Facebook groups devoted
• Macro tracking obsession
• “Keto flu” warnings
• Success story sharing

Criticisms

Concerns emerged:

• Difficult to sustain long-term
• Nutrient deficiencies possible
• High saturated fat questions
• Kidney/liver stress
• Environmental impact (meat-heavy)
• Social limitations

Decline (2020+)

Trend fading:

• Sustainability issues
• Restrictiveness burnout
• Newer diets emerged
• Moderate approaches preferred
• Still exists, less hyped

Sources:

• Keto Diet Research Studies
• Low-Carb Product Market Data
• Nutrition Trend Analysis