Health and Longevity: Obesity Insights

Health and Longevity

• Focus on physiological age, not chronological age.
• This is what determines our health.
• Modern diseases are not the result of aging but lifestyle diseases.

Obesity

• Obesity is not a disease, but a marker for disease.
• Risk factor for lifestyle diseases.
• Methods of defining obesity:
  • Waist circumference
  • Body fat percentage
  • BMI
  • DEXA (visceral vs. subcutaneous fat)
• Excess fat is called ectopic fat.
  • Men tend to gain weight in the stomach, women in the thighs.
  • Women are obese if waist circumference is greater than 88cm / 35in.
  • Men are obese if greater than 102cm / 40in.
  • Waist circumference is a better indicator of health than BMI.
• In the US:
  • 35.9% of the population has a normal BMI.
  • 36% are overweight.
  • 27% are obese.
• Obesity is not about appearance, it’s a marker for disease.
  • Two-thirds of the population is at risk or already has lifestyle diseases.

Diet and Exercise

• Diet is much more important than exercise in terms of effects on the body.
• The quantity of calories is important, but the quality is more significant.
• Food vs. Nutrition:
  • Food = what we ingest
  • Nutrition = the science of food and how it’s digested.
  • Digestion = breaking down large molecules into small ones.
  • Quickly digested food will make us hungry faster.
• We eat for energy. Food is fuel and is needed by every cell in our body.
• Absorption = the movement of food from the small intestine into the bloodstream.
  • Quick digestion = quick absorption.
• The science of food was not taken seriously until the ‘80s.
• Metabolism = what we do with the food / how it’s processed.
• Nutrition = the science of digestion, absorption, metabolism and how food is stored.
• Energy usage is 24/7.
  • The question is how much are you storing and where are you storing it?
• Food is stored in three places:
  • The Liver (limited capacity)
  • Muscles (limited capacity and activity-dependent)
  • Adipose tissue (fat cells)
• Ectopic fat = fat that is somewhere it doesn’t belong.
• Two factors that affect food choices:
  • Price
  • Taste
• Friends/communities tend to have the same health habits.
• Why is nutrition important?
  • It affects diseases partially:
    • Osteoporosis (bone-thinning due to lack of calcium)
  • It affects diseases highly:
    • Heart diseases
    • Diabetes
    • Hypertension
    • Lifestyle diseases in general
• Vitamins are important for metabolism, and deficiency or toxicity can lead to problems.
  • Pellagra is a disease caused by niacin deficiency (vitamin B3).
• Healthy People 2030 is a set of objectives that the medical community sets as goals for the next ten years.
  • It includes strategies and encouragement.
  • Unfortunately, it is not working.
• Vegetables and fruits have a lot of vitamins and minerals and help with satiety.

Body Composition

• Body weight = total body mass.
  • Units = pounds (lbs) or kilograms (kg)
  • Conversion between lbs and kg: weight (lbs) x 0.45 = weight (kg)
• Body composition = bf %; definition: proportion of fat to lean mass in the body expressed as a percentage.
  • Provides a general idea of excess fat.
  • For the general population, the "healthy" body composition ranges from 15% to 25%.

Exercise

• Exercise is stress.
• Beneficial stress is good.
• Too much stress is bad, not enough doesn’t have benefits.
• General adaptation syndrome:
  • Alarm phase
  • Resistance phase
  • Exhaustion
• Adaptation varies from person to person.
  • Alarm: The body is on alert.
  • Resistance development: Muscles are fatigued and know to store more nutrients.
    • Increased size/number of blood vessels for oxygen deliverance.
    • Increased respiratory rate.
    • The higher in adaptation, the harder it is to get to the next level. Beginners advance quickly.
  • Exhaustion:
• Muscle adaptation:
  • Repeated exposure to the same stressors equals adaptation.
  • Skeletal muscles undergo significant modifications in response to stress.
  • Muscle strength = amount of force generated by the muscles.
  • To optimize adaptation, it’s important to take the overload principle into account.
    • Overload principle: Muscles must be worked to capacity to adapt and develop strength and power.
  • Repetition maximum = max amount of weight one can lift in one rep (60-80%).
    • Hypertrophy:
      • Increased force and velocity (how fast a muscle contracts).
      • Increased protein leads to muscle increases.
      • Delayed Onset Muscle Soreness (DOMS) is a sign of adaptation.
  • Specificity: Fat loss cannot be specific to one area of the body.
  • Individual’s principle: Every person is different; there is no "one size fits all" exercise.
  • There is an increase in muscle type conversion during high-intensity exercise.
    • Increase in conversion of type IIx muscle fibers to type IIa fibers.
  • Different genetic makeup, history of activity, aerobic, anaerobic all make a difference.
  • Energy storage in muscle is optimized through resistance training adaptation.

Resistance Training Adaptation

• Intensity of workout is contingent upon the weight of the load.
• Increased loads result in greater muscular adaptation.
• Cross bridges = Muscles interact together.
• Motor units = Brain control of muscles (coordination).
• Force can be increased by increasing proteins in the muscle.
• Sarcomere = Functional unit in muscle cells.

Cardiovascular System

• The coronary circuit is the system of arteries and veins that delivers oxygenated blood to the heart.
  • Right coronary artery (supplies blood to the right side of the heart) and left coronary artery.
  • Left anterior descending artery (delivers blood to the left ventricle).
  • Many heart problems occur in the left coronary artery and left anterior descending artery.
    • These arteries are prone to fat deposits, making them more prone to blockage.
• Atherosclerosis happens to specific blood vessels.
• Heart output:
  • Cardiac output = amount of blood ejected from the blood per minute.
    • Heart Rate x Stroke Volume.
  • CO = amount of blood ejected from the heart every minute (L/min).
  • HR = Beats per minutes (BMP).
  • SV = Amount of blood ejected from the heart every beat (L/beta).
  • CO = 5 L/min at rest, 20 L/min during exercise.

Arteries and Veins

• Arteries take blood away from the heart. They carry blood directly from the heart.

• Veins are the blood vessels that take blood back to the heart.

  • Venule = A small vein.
  • Capillaries = Tiny blood vessels deliver blood to the actual tissue.
  • Arteriole = A tiny artery.

• Every artery has three layers, called tunica:

  • Tunica intima: Innermost layer
  • Tunica media: Middle layer
  • Tunica externa: Outermost layer
  • Lumen = Open space inside artery.

• The outer layer is considered ‘plastic’, meaning it is flexible and elastic.

• Tunica intima is smooth and produces nitric oxide (vasodilator).

• Tunica media can change the diameter of the blood vessel when needed.

• Blood vessels are involuntary smooth muscles; they can undergo vasoconstriction and vasodilation.

• If tissues cannot produce NO, they cannot vasodilate. This leads to a lack of oxygen reaching the tissue.

• High blood pressure damages the tunica intima, resulting in lower NO production, which hinders vasodilation and the ability to accommodate large quantities of blood.

  • When capacity is reached, blood is sent to muscles and adipose tissue.

Chemical Composition

• Monosaccharides = Smallest molecule of carbohydrates.
  • Simplest sugar.
  • Naturally very rare (some in fruit and honey).
• Disaccharides = Two molecules of sugar connected together.
  • The majority of food we consume contains this.
• Polysaccharides = Many molecules connected together as a chain.
  • Polysaccharide = Complex carbohydrates.

Monosaccharides

• Glucose = Universal/ most abundant form of carbohydrates.
  • Preferred molecule in the body.
  • Everything gets converted into glucose.
• Fructose = Sweetest (sweeter than glucose).
• Galactose = Least abundant.
  • It does not exist alone naturally in large amounts.
• Glucose and fructose are used by bacteria, galactose is not, so it does not cause tooth decay.

Disaccharides

• Lactose = Glucose + galactose.
  • Found in dairy products.
• Sucrose = Glucose + fructose.
  • Very sweet.
  • Food companies have converted complex carbohydrates in corn to glucose (High Fructose Corn Syrup) because corn is a cheap resource.
• Maltose = Glucose + glucose.
  • Not very common.

This quiz explores the critical relationship between health, physiological age, and lifestyle diseases, particularly focusing on obesity as a health marker rather than a disease. Learn how different methods for defining obesity provide insights into well-being and disease risk. Understand the implications of obesity statistics in the US and the importance of waist circumference over BMI.