Nutrition and Weight Management
Energy and macronutrients
Carbohydrate and protein supply 4 kcal/g, fat 9 kcal/g, and alcohol 7 kcal/g. Nine amino acids are essential; a "complete" protein supplies all nine in adequate amounts. General fat intake is 20–35% of calories, fiber roughly 25–38 g/day, and hydration should be individualized - pale-yellow urine and pre/post session weigh-ins are practical markers.
Weight-management math
A pound of fat stores roughly 3,500 kcal, so a deficit of about 500 kcal/day yields close to 1 lb (0.45 kg) per week. Weight loss requires an energy deficit; spot reduction does not exist. Protein needs: RDA 0.8 g/kg for sedentary adults, about 1.2–1.7 g/kg for active clients, up to roughly 2.0 g/kg for strength athletes. Carbohydrate needs scale with training - about 3–5 g/kg general, 5–7 g/kg moderate endurance, and 6–10+ g/kg for heavy endurance loads.
Timing and scope
Pre-exercise meals favor carbohydrate with moderate protein and low fat/fiber; post-exercise carbohydrate plus protein supports recovery. Glycogen loading is for endurance competition, not general fitness.
Trap: questions that push specific meal plans, supplement dosing, or calorie prescriptions cross the scope of practice - a certified trainer educates generally and refers to a registered dietitian. Also watch "essential" versus "nonessential" amino acid wording.
Worked example: A 70 kg client eating 2,100 kcal/day wants to lose weight. A 500 kcal deficit gives 1,600 kcal/day. Protein at 1.6 g/kg = 112 g (448 kcal); fat at 25% = about 44 g (396 kcal); carbohydrate fills the rest at roughly 190 g.