Body fat often carries a negative connotation. Yet, this biological feature is universal; we all possess it to varying degrees.
It shapes our physique, influences our energy levels, affects our self-esteem, and plays a pivotal role in our overall health.
What is truly fascinating is how this essential biological resource can serve numerous beneficial purposes yet garner such a negative reputation when present in excess or deficit.
This article aims to demystify body fat, elucidate its functions, and offer guidance on managing it effectively.
What is Body Fat, and What Role Does It Play?
Body fat is essentially the storage of dietary lipids within specialized cells in adipose tissue. It serves two primary functions: acting as a reserve energy source and providing insulation to maintain a stable internal body temperature.
The Dual Nature of Body Fat: White and Brown
Body fat is not monolithic; it is categorized into two distinct types—white fat and brown fat. Each type has its unique composition and function.
Brown fat is rich in iron, minerals, and mitochondria, giving it distinct coloration. Its primary role is to metabolize glucose and triglycerides to regulate body heat.
On the other hand, white fat primarily consists of lipids and fatty acids and serves as a long-term energy storage unit.
The Storage Locations: Subcutaneous and Visceral Fat
Body fat is stored in two prominent locations within the human body: just beneath the skin (subcutaneous) and around internal organs (visceral).
While subcutaneous fat may have aesthetic implications, it is generally benign.
Visceral (Intra-abdominal) fat, however, is a different story. According to the Centers for Disease Control and Prevention (CDC), visceral fat significantly contributes to various health issues, including heart disease, stroke, diabetes, respiratory problems, and even cancer.
This type of fat is also influenced by hormonal changes, particularly the stress hormone cortisol.
Optimal Body Fat Percentages for Adults
For adults aged 55 and above, a healthy body fat percentage based on CDC recommendations ranges from 20% to 25% for women and 10% to 15% for men. These ranges exist due to their direct association with predispositions for visceral fat storage in those with higher than recommended body fat percentages.
Various methods exist for measuring body fat, including calipers, body scans, hydrostatic weighing, and bioelectrical impedance.
These assessments are available at numerous medical, nutritional, and fitness centers. This is an excellent number to know as it demystifies the number produced by the scale and gives you a crystal ball view of your current and future health (as many preventable health factors are tied to Body Mass Index).
Beneficial Functions of Fat
- Thermoregulation: While most people know that fat provides insulation, they may not realize that it is critical in thermoregulation. Brown adipose tissue, or brown fat, generates heat by metabolizing fatty acids, which are essential for maintaining body temperature, especially in cold environments.
- Hormone Production: Fats are essential for producing hormones like testosterone and estrogen. These hormones are lipid-based and rely on the availability of specific fatty acids for their synthesis, playing a crucial role in various physiological processes, including growth, metabolism, and mood regulation.
- Vitamin Absorption: Fat aids in absorbing fat-soluble vitamins such as A, D, E, and K. These vitamins are essential for various functions, including vision, bone health, and blood clotting. The body cannot absorb these vitamins effectively without adequate fat, leading to potential deficiencies.
Detrimental Functions of Excess Body Fat
- Inflammation: Excessive fat, particularly visceral fat, can produce pro-inflammatory substances contributing to chronic inflammation. This state of low-level inflammation is linked to various diseases, including cardiovascular disease, diabetes, and even some cancers.
- Insulin Resistance: High levels of fat, especially saturated fats, can lead to insulin resistance, a condition where the body’s cells become less responsive to insulin. This can result in elevated blood sugar levels, increasing the risk of type 2 diabetes.
- Cognitive Decline: Emerging research suggests that excessive fat intake, particularly saturated, may be linked to cognitive decline and an increased risk of neurodegenerative diseases like Alzheimer’s. The mechanisms are not yet fully understood but may involve inflammation and oxidative stress.
Strategies for Managing Excess Body Fat
If you find yourself grappling with excess body fat, the key to reduction lies in triggering a metabolic process known as lipolysis. This enzyme-driven chemical reaction breaks down fatty acids into simpler components used as energy.
The Mechanics of Lipolysis
Lipolysis is demand-driven. When you expend more energy through physical activity than you consume through your diet, your body taps into its stored fatty acids to make up the deficit.
For instance, maintaining a daily caloric deficit of 500 to 750 calories AND LIMITING DIETARY SUGAR/SIMPLE CARBOHYDRATES will prompt your body to utilize stored fat, initiating the fat-loss cycle.
However, extreme caloric restriction can be counterproductive. Depriving your body of too many calories can also lead to muscle wastage, slowing your metabolism and reducing energy levels. This is why losing weight through diet alone (sans exercise) is much less efficient, reduces sustainability, and typically causes chronic weakness/fatigue.
It is a good practice to never allow yourself to consistently drop below a thousand calories daily.
The Caloric Equation
Each pound of body fat equates to approximately 3,500 calories. Therefore, a daily caloric deficit of 500 calories would lose about one pound of body fat over a week. To accelerate this process, increasing physical activity is recommended.
For example:
| Activity | Calories Burned per Hour for a 155-pound Person | Calories Burned per Hour for a 185-pound Person |
| Running (6 mph) | 704 | 839 |
| Swimming (freestyle) | 383 | 493 |
| Cycling (12-14 mph) | 493 | 587 |
| Rowing (moderate) | 493 | 587 |
| Jumping Rope | 704 | 839 |
| Hiking | 422 | 503 |
| Dancing | 317 | 378 |
| Yoga | 211 | 251 |
| Weightlifting (moderate) | 211 | 251 |
| Walking (3.5 mph) | 211 | 251 |
The Holistic Approach
The cornerstone of long-term success in managing body fat lies in identifying the root causes of excess fat accumulation—be it recreational eating, habitual snacking, stress, excess sugar intake, or a sedentary lifestyle—and taking sustainable steps to address them.
Remember, not just the quantity but the quality of your diet matters. A balanced diet, an active lifestyle, and regular exercise can be your best allies in conquering the battle against excess body fat and preventative consequences of over-weight aging.
Joe Carson B.S. NASM-CPT/FAS/CN
Master Trainer/Functional Aging Specialist/Certified Nutritionist
Twenty-First Century Aging