Fat: Friend or Foe?

"Dr. Aaron Cypress of the diabetes, endocrinology, and obesity branch of NIH eloquently captures the prevailing perception of fat: an unwelcome companion that many strive to shed, causing more anguish than awe."

Delving into the depths of his insight, we uncover a richer understanding.

In a "lean" adult, fat tissue constitutes roughly 30-40% of total body mass in women and 15-20% in men. While pinpointing precise total body fat remains challenging without CT scans or MRIs, waist circumference, BMI, and bioimpedance scales offer reasonable approximations.

But it's not merely the quantity of fat that matters; its location carries equal significance. Fat around our organs bears more risk than the subcutaneous variety. This nuance is why BMI alone sometimes paints a deceptive picture.

Contrary to the belief that fat cell count remains constant throughout life, recent revelations debunk this notion. The entire population of fat cells regenerates every 15 years or so.

Fat tissue primarily exists in two forms: white and brown (with shades in-between). The elusive transformation of white fat into desirable brown fat is a topic of intrigue.

White fat serves as our energy repository, liberating us from constant hunger to channel efforts into civilization's growth. It furnishes insulation against the chill and external forces, releasing hormones like leptin and adiponectin that influence appetite, metabolism, and inflammation.

Remarkably, white fat can also induce inflammation under certain conditions. In obesity, overgrown fat cells suffer oxygen deprivation, releasing inflammatory hormones that underpin heightened risks of heart attacks, cancer, and infection susceptibility, such as COVID-19.

White fat is pivotal for reproductive system function. Anorexia's dearth of fat can hinder menstruation, while excess fat can expedite puberty. Breastfeeding hinges on fat availability; an excess, conversely, exacerbates cancer and heart disease risks.

Brown fat takes the spotlight for heat generation. It dispatches hormones that ramp up metabolism, enhancing glucose and fat consumption by our muscles. Though comprising a mere 0.2-3% of total body fat, brown fat's activation, beneficial in mice, holds tantalizing prospects for humans, necessitating further investigation.

Age, elevated BMI, and higher ambient temperatures suppress brown fat. The role of specific macronutrients—carbs, fat, protein—in weight gain remains a fiery debate that shall be explored in subsequent blogs.

In summation, fat, in measured proportions, plays a harmonious role. Optimal fat levels vary across individuals, contingent on factors like race, sex, and age. While research journeys onward, embracing a watchful BMI (accounting for race-specific ideals), embracing an active lifestyle, and practicing portion control present minimal drawbacks.

A pragmatic gauge of healthy body fat is waist circumference—ideally below 35 inches for women and 40 inches for men. These insights, woven into the fabric of Dr. Cypress's wisdom, foster a healthier, well-rounded perspective on fat.