Why Were We So Thin In The 70s (The Truth Will Surprise You)

Fiber slows gastric emptying and glucose absorption
Chewing and digestion enhance satiety signaling

Ultra-processed foods—now known to override appetite regulation—were rare. Modern research shows these foods increase calorie intake even when macronutrients are matched, due to palatability engineering and rapid absorption.
3. Predictable Eating Rhythms and Hormonal Regulation

Most individuals ate three structured meals per day, with minimal snacking.

This pattern supported:

Stable insulin signaling
Proper leptin (satiety hormone) sensitivity
Clear ghrelin (hunger hormone) rhythms

Frequent grazing, now common, disrupts these hormonal cycles and encourages persistent insulin elevation—promoting fat storage over fat utilization.

The body responds best when feeding and fasting periods are clearly defined.

4. Smaller Portions and Caloric Awareness

Portion sizes were substantially smaller:

Soft drinks came in modest bottles
Plates held less food
No automatic portion inflation

Portion size strongly influences intake independent of hunger. Studies consistently show that people eat more when served more—without compensating later.