The Physics of Unfairness: Why Your Husband Eats More and
"Witches" Don't Get Fat
We all know that person. They order a double burger, wash it down with cola, ignore the gym, and still wear a size XS. Or your husband, who decides to "lose a little weight," stops eating bread for dinner, and drops 5 kg in a week while you weigh every lettuce leaf. It feels like magic or injustice. But from the perspective of human body engineering — it is pure mathematics and thermodynamics.
Let's break down why comparing your plate to someone else's is a bug in your weight loss code.
Myth 1: "She Just Has a Fast Metabolism"
Science says: unlikely. Metabolic rate correlates with body size for most people. The "magic fire" that burns pizza without a trace does not exist.
In 2009, the BBC conducted a revealing experiment ("Why Are Thin People Not Fat?"). They took 10 thin volunteers who claimed they "eat whatever they want" and forced them to consume 5,000 kcal per day for 4 weeks. They were also forbidden to exercise. The result? Everyone gained weight. Physics could not be fooled.
However, an interesting bug occurred. One participant (an ethnic Chinese man) gained the least amount of fat but increased his muscle mass. Why? His body activated a defense mechanism — NEAT.
The Secret Weapon: NEAT (Non-Exercise Activity Thermogenesis)
NEAT is the energy we expend for everything that is not sleeping or sports: gesturing, tapping a foot under the table, pacing while talking, maintaining posture.
Research by Dr. James Levine (Mayo Clinic) showed that people with high NEAT levels can burn an additional 350-500 kcal per day just by "sitting" still. When you overfeed a "thin witch," she subconsciously starts moving more. Her body tries to "shake off" excess energy as heat and micro-movements.
The body of a person prone to weight gain, conversely, switches to "power-saving mode" and glues you to the couch.
Gender Inequality: Men vs. Women
Why do men lose weight easier? Two factors are at play here, and neither is "willpower."
1. Size matters. Men are on average 15-20 cm taller and have a heavier skeleton. A larger "machine" requires more fuel just for idling.
2. Muscle mass. Men have a higher percentage of muscle mass due to testosterone. Muscle is metabolically active tissue. Even at rest, 1 kg of muscle consumes more calories than 1 kg of fat.
When a woman tries to eat her husband's portions, she ignores the fact that his BMR (Basal Metabolic Rate) can be 400-600 kcal higher than hers. It's like filling a compact car with fuel for an SUV — the tank will simply overflow.
The Perception Trap
Another crucial nuance is subjectivity. We see a "skinny friend" eating a huge pizza at a party. We think: "She eats like this always." But we don't see that she skipped breakfast because she "forgot" and had an apple for lunch.
Her appetite regulation mechanisms (leptin/ghrelin) work correctly: after overeating, she simply won't want to eat the next day. People with impaired insulin or leptin sensitivity (or "food noise") lack this stop-cock. For us, "a lot of food" is subjectively little, but for them, it is physically impossible to cram in.
Conclusions
- Don't copy other people's plates. Your energy expenditure is a unique dataset (weight, height, muscle, NEAT).
- Move in micro-movements. Increasing NEAT (walking more, standing instead of sitting) is more effective for long-term weight loss than an hour at the gym three times a week.
- Trust data, not eyes. Use Calorize to find out your real BMR rather than relying on your partner's appetite.
References
- 1 Levine, J. A. (2002). Non-exercise activity thermogenesis (NEAT). Best Practice & Research Clinical Endocrinology & Metabolism. https://pubmed.ncbi.nlm.nih.gov/11963628/
- 2 BBC Horizon. (2009). Why Are Thin People Not Fat? [Documentary].
- 3 Tarnopolsky, M. A. (2000). Gender differences in metabolism; nutrition and supplements. Journal of Science and Medicine in Sport. https://pubmed.ncbi.nlm.nih.gov/11140287/