Nutrition and Weight Management
Domain 4 tests general nutrition education and weight-management coaching - and the boundaries of your scope. Expect energy-balance math, macronutrient ranges, hydration numbers, and scope-of-practice scenarios.
Energy balance and body weight
- Weight change follows energy balance. A deficit of about 500 kcal/day produces roughly 1 lb (0.45 kg) of loss per week; 250 kcal/day yields about 0.5 lb/wk.
- A prudent target is 0.5–1 kg (1–2 lb) per week; slower loss better preserves lean mass.
- Fuel values: fat ~9 kcal/g, carbohydrate and protein ~4 kcal/g, alcohol ~7 kcal/g.
Macronutrients and distribution
- Carbohydrate 45–65% of calories; it is the primary fuel for moderate-to-high intensity work and restores glycogen.
- Fat 20–35%, favoring unsaturated sources; protein 10–35%, with an RDA of 0.8 g/kg and roughly 1.2–2.0 g/kg for regularly training clients.
- Fiber about 25–38 g/day. On a label, read the serving size first, then calories and protein per serving.
Hydration
- About 5–7 mL/kg of fluid roughly 4 hours before exercise (about 500 mL for a 70 kg client), then 150–250 mL every 15–20 min during work.
- Replace 16 oz (about 475 mL) for every pound of body weight lost during exercise.
Worked example
A client eats an estimated 2,600 kcal/day and is weight-stable. To lose about 1 lb per week, target roughly 2,100 kcal/day - a 500 kcal deficit. Rather than cutting all 500 from food, add about 250 kcal of daily activity and trim about 250 kcal from intake; the split deficit is usually easier to sustain and protects adherence.
Traps
Prescribing a diet, calorie target, or supplement - refer to a registered dietitian; promising spot reduction; stating protein needs as a percentage when the client needs g/kg; ignoring medications and medical conditions; and treating one weigh-in as a trend rather than a data point.