Energy and Metabolism Flashcards
What is the meaning of energy metabolism in the human body?
Energy metabolism is how we break down molecules and put them to use in the body
What is the metabolic syndrome?
a cluster of abnormalities linked to mismanagement of fuel (inefficient energy metabolism)
In conventional medicine, to be called metabolic syndrome it needs 5 symptoms:
- HBP
- High blood sugar
- High blood triglycerides
- High LDL cholesterol
- Excessive abdominal fat
=> they all are symptoms of suboptimal energy metabolism
What is energy intake influenced by?
- Food choices
- Psychologies and emotions
- Food environment
- Appetite
- Food reward
What is energy intake influenced by?
- Food choices
- Psychologies and emotions
- Food environment
- Appetite
- Food reward
What is the 1st law of thermodynamics
Energy cannot be created or destroyed but it can be transformed from one form to another
Forms of energy incl. chemical, mechanical and electrical => all of which can be converted to heat
The chemical energy obtained from food is used to perform which works x3?
- Chemical work = synthesis of ATP, hormones and enzymes
- Mechanical work => muscular contraction, walking, running, heart beating, eyes blinking
- Electrical work = maintenance of zoning gradients across membrane
What is the equation of energy balance? What creates an imbalance?
Energy balance = energy intake + energy stores - energy expenditure
If the intake and expenditure are not equal => imbalance of energy
- Negative energy balance = of body’s energy stores (glycogen in liver and muscles, fat, protein)
- Positive energy balance = increase in body energy stores primarily as fat
what is the 2nd law of thermodynamics?
All energy used by the body degenerate as HEAT => when energy is transferred of transformed there is a loss in energy in the form of heat
What is a calorie ? How much calorie is there is the following macronutrients?
A calorie is the amount of heat required to raise the temperature of 1g of water by 1 degree Celsius.
Heat generating potential of a food
Energy in macronutrients:
- 1g Carbs = 4kcal
- 1g protein = 4kcal
- 1g fat = 9kcal
- 1g alcohol = 7kcal
- 1g fibre = 2kcal (yielded from bacteria fermentation in the gut)
How does Mitochondria produces ATP (steps)?
What key nutrients are required for ATP production?
What can damage mitochondria?
- Glycolysis, production of Acetyl CoA, Krebs Cycle, ETP
Red Blood Cells have no mitochondria
Key nutrients for ATP production: Magnesium, Manganese, Iron, Sulphur, CoQ10, Copper, B1, B2, B3 and ALA
Damage to mitochondria and interfere with energy production: nutrient deficiencies, toxins (poor liver detox and elimination pathways), heavy metals
What factors contribute to energy production (ATP production) and why?
- Sufficient nutrient intake = crucial for cell respiration and the Krebs cycle
- Digestion and absorption = Digestion is key for liberation of nutrients and Good GI health vital for Absorption
- Respiratory health = O2 intake vital for ATP production and the ETC
- Heart and circulatory health = deliver nutrients to cells
- Mitochondrial health = Mitochondria require nutrients, and antioxidants ans minimal toxic load (incl. sugar)
- Thyroid health = governs the activity of mitochondrial cells
- Adrenal health = Adrenaline and noradrenaline increase energy delivery (stimulate glycolysis and increase HR and BP). Adrenals need Vit C, B vitamins and magnesium to create these hormones and cortisol. Can deplete the body from these nutrients when we are under chronic stress and these nutrients are key in ATP production
- Healthy detoxification
- Sleep hygiene = promotes melatonin production (antioxidant) restore energy supply when we sleep
==> MOOD is a major factor in energy levels. Having a goal, acts of kindness, being in love create energy.
What 3 variable factors energy expenditure depends on and how much they each represent in Total energy expenditure?
Basal Metabolic Rate (BMR) = 65-75%
Physical Activity (20%)
Thermic Effect of Food = 10%
BMR = BMR account for 65-75% of total energy expenditure in a day mostly from the metabolic activity of lean tissues (non adipose) referred as Fat-Free Mass (FFM) = muscles and organs. BMR varies between individuals
Physical activity can impact BMR as exercice can elevate metabolic rate for up to 48h post exercice (excess post exercice oxygen consumption)
Other factors that impact BMR are caffeine, stress, nicotine, medication, fever, injury, genetics, thyroid hormones etc.
Thermic Effect of Food (TEF) = energy required to digest food you eat = thermogenesis.
What is the role of the thyroid hormone in energy metabolism?
What is subclinical hypothyroidism? Signs and symptoms. Root cause?
Thyroid gland regulates energy metabolism by secreting thyroid hormone that control the metabolic rate of cells.
TSH is produced by the anterior pituitary gland and trigger the release of FT4 and FT3 from the thyroid gland. This process require: Iodine, selenium for conversion as well as zinc, iron and tyrosine.
Subclinical hypothyroidism is found in 8-10% of the population = when TSH is above range but T3 and T4 are normal
Signs and symptoms = low energy, reduce appetite, weight gain, feeling cold, dry skin, thinning hair, constipation, irregular period, depression
Root cause = nutrient deficiency, autoimmunity, fluoride, mercury and chlorine exposure, endocrine disrupters like BPA.
What is the impact of disease on the energy metabolism?
Infection and fever can raise BMR
Energy requirement increase after surgery or injury
BMR of a patient with severe burn doubles
Cancer patient need energy requirements of 145% their BMR
What are the various TEF of foods?
Fat = 0.3%
Carbs = 5-10% - depends on how much fibres
Protein = 20-30%
What is over-eating ? What does it lead to? What is de novo lipogenesis
What about Fructose?
Over-eating is when excess calories are consumed.
Excessive carbs, especially refined (+ sedentary lifestyle) lead to de novo lipogenesis (DNL) (metabolic pathway that synthesised fatty acids from excess carbs) It is a a key driver in metabolic syndrome
Converting carbs to fatty acids via DNL is a costly process requiring up tp 30% of the carbs energy to do so (exception of Fructose)
High level of fructose lead to high DNL because easily converts to fatty acids
Fats consumed in excess are stored in adipose tissue
What are the macronutrients ratios for the following diets:
Keto
Blue zone
Standard American Diet (SAD)
Keto = 65% fat / 25% protein / 10% carbs
Blue zone = 20% fats / 15% protein / 65% carbs
SAD = 30% fat / 20% protein / 50% carbs
Explain the process of Ketosis in the body?
What are the benefits of ketosis ?
When glucose intake in insufficient to maintain glycogen stores in the liver and in the muscles, the brain experience a stress => increase in cortisol and sharp drop in insulin production => fat cells open up and glowed the blood with fatty acids.
Ketones are produced
Burning fat as a fuel is a cleaner energy source because less oxidative stress
=> turns up insulin sensitivity
=> For Alzheimer’s our brain cell become insulin resistant and neurones die
=> Cancer fuel on glucose and not on ketone bodies
