Pg 1-15 Flashcards
(18 cards)
What three factors are involved in body weight regulation?
Energy intake, energy storage, and energy expenditure
How can a small daily calorie surplus affect long-term health?
A surplus of just 25 kcal/day can lead to morbid obesity over time
What does the 1st Law of Thermodynamics state?
Energy cannot be created or destroyed, only transformed from one form to another
How do animals obtain energy, according to the 1st Law of Thermodynamics?
From chemical energy stored in plants and other animals
What types of work require energy in the human body?
Chemical work (e.g. macromolecule synthesis)
Mechanical work (e.g. muscle contraction)
Electrical work (e.g. ion gradients)
What is the equation for energy balance?
Energy intake + energy stores – energy expenditure
What happens in a negative energy balance?
The body uses glycogen, fat, and then protein for energy
What happens in a positive energy balance?
Excess energy is stored, primarily as fat
When energy is in short supply the body can source energy from?
Glycogen (liver and muscle)
Fat (main form)
Protein (used as a last resort) - in cases of starvation or malnutrition. Amino acids are liberated from tissues such as skeletal muscle.
What does the 2nd Law of Thermodynamics state?
All energy used by the body degenerates as heat.
Whenever energy is transferred or transformed (e.g. during cellular metabolic reactions) there is a loss of energy in the form of heat.
What is a calorie in physical terms?
The amount of heat required to raise the temperature of 1g of water by 1°C.
What does the term ‘calorie’ usually refer to in nutrition?
A kilocalorie (kcal), or 1,000 calories
How much energy is provided per gram by each macronutrient?
Carbohydrate: 4 kcal/g
Protein: 4 kcal/g
Fat: 9 kcal/g
Alcohol: 7 kcal/g
Fibre: 2 kcal/g (from fermentation)
What is ATP and where is it produced?
ATP (adenosine triphosphate) is the body’s energy currency, produced in the mitochondria
What processes in mitochondria produce ATP?
Acetyl CoA formation, Krebs cycle, Electron Transport Chain
What nutrients are essential for ATP production?
Mg, Mn, Fe, S, CoQ10, Cu, B1, B2, B3, B5, alpha-lipoic acid
What factors can impair mitochondrial energy production?
Nutrient deficiencies, toxins, heavy metals, poor detoxification
What physiological systems support efficient energy production?
Adequate nutrient intake
Healthy digestion and absorption
Lung/respiratory health
Cardiovascular health
Mitochondrial health
Thyroid health
Adrenal health
Healthy detoxification
Sleep hygiene
