Pg 17-28 Flashcards
(25 cards)
Besides calories, how else does food provide energy?
Through micronutrients, phytonutrients, and cofactors that support cellular energy production and metabolic processes.
What are the three main components of total daily energy expenditure?
Basal Metabolic Rate (BMR), 60-75%
Physical Activity, 20%
Thermic Effect of Food (TEF) 10%
What is Basal Metabolic Rate (BMR)?
The minimum energy needed to sustain basic physiological functions such as heartbeat, breathing, and cell repair.
What percentage of total energy expenditure does BMR account for?
Approximately 60–75%.
What primarily influences BMR?
Fat-free mass (muscle and lean tissue), body size, physical activity, and factors like stress, caffeine, medications, and thyroid hormones.
What role does physical activity play in BMR?
It can elevate metabolic rate for up to 48 hours and increase muscle mass, which boosts BMR.
What hormones does the thyroid produce to regulate metabolism?
Thyroxine (T4) and Triiodothyronine (T3), stimulated by Thyroid Stimulating Hormone (TSH).
Which nutrients are essential for thyroid hormone production?
Iodine, tyrosine, zinc, selenium, and iron.
What is subclinical hypothyroidism?
Elevated TSH with normal T3 and T4 levels, often symptomless and more common in women.
What are symptoms and causes of subclinical hypothyroidism?
Symptoms: fatigue, weight gain, cold sensitivity, dry skin, constipation. Causes: nutrient deficiencies, autoimmunity, endocrine disruptors.
How does disease or trauma affect metabolism?
It increases energy requirements for recovery, especially in burns, infections, surgery, cancer, and anorexia nervosa.
What is the Thermic Effect of Food (TEF)?
The energy required to digest and process food, about 10% of daily expenditure.
Which macronutrient has the highest thermic effect?
Protein (20–30%), followed by carbohydrates (5–10%), then fats (0–3%).
How does food processing affect TEF?
Highly processed foods have a lower thermic effect than whole foods.
What are standard caloric guidelines for men and women?
Women: 2000 kcal/day; Men: 2500 kcal/day (actual needs vary).
What factors affect individual energy requirements?
Body size, muscle mass, metabolic health, and lifestyle activity level.
What is de novo lipogenesis (DNL)?
The conversion of excess carbohydrates (especially refined ones) into fat, contributing to metabolic syndrome.
How is fructose different in fat storage?
It is easily converted into fat by the liver, promoting DNL more than glucose.
What happens when fat is consumed in excess of energy needs?
It is stored in adipose tissue under normal metabolic conditions.
What are the effects of under-eating on metabolism?
It slows metabolism, may cause nutrient deficiencies, and can hinder weight loss.
How can someone restore metabolism after chronic under-eating?
By increasing intake of nutrient-dense foods to re-establish metabolic balance.
What is the role of macronutrients in energy balance?
They help calculate energy intake, but food quality is more important in naturopathic nutrition.
How can macronutrient ratios be personalised?
Through nutrigenomic testing, which assesses genetic metabolism of fats and carbs.
What are typical macronutrient ratios for weight goals?
Weight loss: High protein, low carb & fat; Maintenance: Moderate protein, carb & fat; Muscle gain: High protein, high carb, low fat.
