CCN cheat sheet

BMI = weight (kg) / height (m)^2; adult cutoffs: underweight <18.5, normal 18.5-24.9, overweight 25.0-29.9, obesity >=30.0 kg/m^2.

Ideal body weight (Devine): men 50 kg + 2.3 kg per inch over 5 ft; women 45.5 kg + 2.3 kg per inch over 5 ft.

Percent weight change = (usual weight - current weight) / usual weight x 100; >5% in 1 month or >10% in 6 months flags significant loss.

Albumin half-life ~20 days and prealbumin ~2 days; both are negative acute-phase reactants, so inflammation lowers them independent of intake.

Nitrogen balance = nitrogen intake - (urinary urea nitrogen + 4 g); positive balance indicates anabolism, negative indicates catabolism.

24-hour recall depends on memory and single-day intake; a food frequency questionnaire captures usual pattern over weeks to months.

Handgrip dynamometry and gait speed are functional measures that decline before anthropometric changes in malnutrition.

Waist circumference thresholds: >102 cm (40 in) in men and >88 cm (35 in) in women indicate elevated cardiometabolic risk.

MUST screening scores BMI, unplanned weight loss, and acute disease effect; a total of 2 or more triggers a formal nutrition care plan.

A 5-10% reduction in body weight lowers blood pressure, improves glycemic control, and reduces progression to type 2 diabetes in at-risk adults.

150 minutes per week of moderate-intensity aerobic activity plus 2 resistance sessions weekly is the standard adult movement target.

DASH pattern emphasizes fruits, vegetables, low-fat dairy, and potassium; sodium reduction to <2300 mg/day lowers systolic pressure by roughly 5-6 mmHg.

A 500 kcal/day deficit yields approximately 0.45 kg (1 lb) of fat loss per week; deficits above 1000 kcal/day rarely improve adherence.

Soluble fiber (5-10 g/day, e.g., beta-glucan, psyllium) lowers LDL cholesterol by binding bile acids and increasing their excretion.

Glycemic index ranks a food's carbohydrate effect against glucose; glycemic load = GI x available carbohydrate (g) / 100.

Transtheoretical model stages: precontemplation, contemplation, preparation, action, maintenance; relapse is a normal cyclical event, not failure.

Sleep restriction to under 6 hours raises ghrelin and lowers leptin, increasing hunger and appetite for energy-dense foods.

Alcohol provides 7 kcal/g and suppresses fat oxidation; intake should be limited to <=1 drink/day for women and <=2 for men.

Vitamin D3 (cholecalciferol) is more potent than D2 at raising serum 25-hydroxyvitamin D; typical repletion dosing is 1000-2000 IU/day.

Calcium absorption depends on vitamin D; total elemental calcium above ~500 mg per dose is poorly absorbed, so split doses.

Vitamin B12 is absorbed via intrinsic factor in the ileum; oral high-dose or sublingual forms bypass this in pernicious anemia.

Iron absorption is enhanced by vitamin C and inhibited by phytates, tannins, and calcium; ferrous salts are best taken on an empty stomach.

Folic acid supplementation before and during early pregnancy reduces neural tube defects; 400 mcg/day is the standard preventive dose.

Omega-3 EPA/DHA supplementation lowers triglycerides at doses of 2-4 g/day but has minimal effect on LDL cholesterol.

Magnesium oxide has high elemental content but low bioavailability; magnesium citrate and glycinate are better absorbed.

Probiotic efficacy is strain-specific; benefits from one species or strain do not transfer to another, so label strain identity matters.

Fat-soluble vitamins (A, D, E, K) accumulate in tissue and carry toxicity risk at high doses; water-soluble excess is generally excreted.

Glycolysis converts glucose to 2 pyruvate, yielding 2 ATP and 2 NADH; pyruvate dehydrogenase then forms acetyl-CoA for the citric acid cycle.

Beta-oxidation cleaves fatty acyl-CoA two carbons at a time, producing acetyl-CoA, FADH2, and NADH; ketogenesis follows when acetyl-CoA exceeds cycle capacity.

The electron transport chain uses oxygen as the final electron acceptor; oxidative phosphorylation yields roughly 30-32 ATP per glucose.

Insulin activates PI3K/Akt signaling, translocating GLUT4 to the membrane in muscle and adipose to increase glucose uptake.

Glucagon and cortisol raise blood glucose via glycogenolysis and gluconeogenesis; cortisol also drives proteolysis and lipolysis.

Hepatic gluconeogenesis supplies most blood glucose during fasting beyond ~8-12 hours, using lactate, glycerol, and amino acids.

The urea cycle converts ammonia to urea in the liver; its rate is limited by enzyme capacity and substrate availability.

Leptin signals adiposity to the hypothalamus to suppress appetite; ghrelin from the stomach rises pre-prandially to stimulate hunger.

mTORC1 drives protein synthesis in response to amino acids and insulin; AMPK senses low ATP and inhibits mTORC1 to favor catabolism.

Wound healing phases: hemostasis (minutes), inflammation (days 1-3), proliferation (days 4-21), and remodeling (weeks to months).

Collagen synthesis requires vitamin C as a cofactor for prolyl and lysyl hydroxylase; deficiency impairs cross-linking and tensile strength.

Zinc is a cofactor for matrix metalloproteinases and DNA-binding proteins; deficiency delays epithelialization and wound closure.

Protein needs rise during recovery from injury or surgery, commonly 1.2-2.0 g/kg/day depending on wound burden and renal status.

Arginine and glutamine support immune cell and enterocyte proliferation; their demand rises in catabolic states.

Muscle protein synthesis peaks with 20-40 g of high-quality protein per meal; leucine acts as a key signaling trigger.

Autophagy clears damaged organelles and misfolded proteins; it is upregulated by fasting and exercise and declines with aging.

Oxidative stress from excess reactive oxygen species impairs stem cell function; adequate vitamin E and selenium support antioxidant defense.

Inflammation resolution depends on omega-3-derived resolvins and protectins, which actively terminate the inflammatory phase.