Meal Planner

If body fat % is known, use Katch-McArdle instead of Mifflin-St Jeor — it's more accurate for lean or obese individuals.

Step 2: Calculate Energy Target

Mifflin-St Jeor BMR (validated as most accurate predictive equation for the general population, ±10% for most adults):

Men:   BMR = (10 × weight_kg) + (6.25 × height_cm) − (5 × age) + 5
Women: BMR = (10 × weight_kg) + (6.25 × height_cm) − (5 × age) − 161

Katch-McArdle (use if body fat % is known — more accurate at body-composition extremes):

BMR = 370 + (21.6 × lean_mass_kg)    where lean_mass_kg = weight_kg × (1 − bodyfat%)

TDEE = BMR × activity multiplier:

People consistently overestimate their activity — when in doubt, pick the lower multiplier and adjust upward after 2 weeks of real-world data.

Goal adjustment:

• Fat loss: TDEE − 20–25% (typically 400–600 kcal deficit). Targets ~0.5–1% bodyweight/week. Steeper deficits accelerate muscle loss.
• Maintenance: TDEE ± 0
• Muscle gain: TDEE + 10–15% (typically 200–400 kcal surplus). Larger surpluses mostly add fat, not muscle, in trained individuals.

Step 3: Set Macros — Evidence-Based Targets

Protein (set this first, in g/kg — not as a percentage)

In imperial: 1.6–2.2 g/kg ≈ 0.7–1.0 g/lb. Distribute across 3–5 meals at 0.3–0.4 g/kg per meal (~25–40 g) — muscle protein synthesis response plateaus per-sitting.

Fat

Minimum ~0.5 g/kg bodyweight (hormone synthesis floor). Typical range 0.8–1.2 g/kg, or 20–35% of calories. Going below 20% long-term risks fat-soluble vitamin and hormone issues.

Carbohydrates

Fill remaining calories after protein and fat are set. carbs_g = (target_kcal − protein_g×4 − fat_g×9) / 4

Fiber

14 g per 1,000 kcal (Dietary Guidelines for Americans) — roughly 25 g/day for women, 38 g/day for men at maintenance. Most plans undershoot this. Check it explicitly.

Step 4: Build the Plan

Rotate 3–4 breakfast templates, 4–5 lunch/dinner templates across the week — enough variety to prevent burnout, enough repetition to keep prep and shopping simple.

## Monday — Target: 2,200 kcal | 165P / 220C / 73F

Breakfast (520 kcal): Greek yogurt 250g + berries 100g + granola 40g + chia 10g → 32P / 58C / 14F
Lunch (640 kcal): Chicken breast 170g + brown rice 200g cooked + roasted veg 200g + olive oil 10g → 48P / 62C / 16F
Snack (230 kcal): Apple + almond butter 20g → 5P / 28C / 12F
Dinner (630 kcal): Salmon 150g + sweet potato 250g + broccoli 150g → 42P / 56C / 22F
Pre-bed (180 kcal): Cottage cheese 180g → 22P / 7C / 4F

Daily total: 2,200 kcal | 149P / 211C / 68F | Fiber: ~31g ✓

Nutrition data sources — for accurate macros, query the USDA FoodData Central API rather than guessing:

• Base URL: https://api.nal.usda.gov/fdc/v1/ — free API key from api.data.gov, 1,000 req/hr limit
• Search: GET /foods/search?query=chicken breast&api_key=KEY
• Lookup: GET /food/{fdcId}?api_key=KEY returns full nutrient profile per 100g
• Python clients on PyPI: fooddatacentral (simple), usda-fdc (includes DRI comparison + recipe aggregation)
• Data is public domain (CC0). Branded foods update monthly.

Step 5: Shopping List

Aggregate ingredients across all days, round to purchasable units, organize by store section:

PROTEINS: Chicken breast 1.2kg · Salmon 450g · Eggs 1 dozen · Greek yogurt 1.8kg · Cottage cheese 750g
PRODUCE: Broccoli 2 heads · Sweet potato 1.5kg · Mixed berries 700g · Spinach 300g · Apples 5
GRAINS/PANTRY: Brown rice 1kg · Oats 500g · Granola 300g · Almond butter 1 jar · Chia 100g

Step 6: Meal Prep Logistics

Single prep session (Sun, ~90 min): Cook all grains. Roast two sheet-pans of proteins + veg. Portion into containers. Prep overnight oats for 3 days.

USDA-backed refrigerated shelf life: cooked poultry/meat 3–4 days · cooked fish 3–4 days · cooked grains 4–6 days · cut raw veg 3–5 days. Freeze anything for day 5+.

Fitness Schedule (Condensed)

Beginner (<6 mo): Full body 3×/week (Mon/Wed/Fri). Each session: 1 squat pattern, 1 hinge, 1 push, 1 pull, 1 carry/core. 3×8–12. Simplest progression: add 2.5 kg when all sets hit the top of the rep range.

Intermediate (6 mo–2 yr): Upper/Lower 4×/week. Mon upper-push emphasis, Tue lower-quad, Thu upper-pull, Fri lower-hinge.

Advanced: Push/Pull/Legs 5–6×/week.

Volume guidelines (per muscle group per week, meta-analytic consensus): 10–20 hard sets for hypertrophy. Below 10 is maintenance; above 20 shows diminishing returns and rising injury risk for most.

Rep ranges: 3–6 strength-biased · 6–15 hypertrophy (all ranges build muscle if taken near failure; hypertrophy is not rep-range-specific) · 15+ endurance-biased.

Progressive overload is mandatory — log every session. No log → no plan.

Recovery: ≥1 full rest day/week. 7–9 hrs sleep. Deload (−40–50% volume) every 4–6 weeks.

Cardio: General health → 150 min/week moderate (WHO guideline). Fat-loss phase → add 2–3 × 20–30 min sessions, steady-state or intervals. Muscle-gain phase → keep cardio to 1–2 light sessions to minimize interference.

Output: Always Build a Visual Web App

Every meal plan MUST be delivered as an interactive React + Vite web app. Do not output plans as plain text or markdown — always build and deploy a visual website.

Core Layout: Week-by-Week Calendar View

The app should display the meal plan as a visual weekly calendar grid:

1. Week selector — tabs or navigation for Week 1, Week 2, etc. If the plan has cycling options (e.g., 2-week rotation, high/low carb days), show each cycle as a separate week tab.
2. Day columns — 7 columns (Mon–Sun), each showing all meals for that day as stacked cards.
3. Meal cards — each card shows:
   • Meal name (Breakfast, Lunch, Dinner, Snack)
   • Food items with portions
   • Per-meal macros: P / C / F / kcal
   • Color-coded macro bar (protein=blue, carbs=amber, fat=red)
4. Daily summary row — bottom of each column shows daily total kcal and macro breakdown vs target (with green/yellow/red indicator for on-target/close/off)

Multiple Options & Cycling

• Meal swaps — for each meal slot, offer 2–3 alternatives the user can click to swap in. Show a small "swap" icon on each meal card that reveals alternatives in a dropdown or modal.
• Rotation plans — if the user wants variety (e.g., "don't repeat the same dinner twice in 2 weeks"), build a 2-week rotation with different week tabs.
• High/low day cycling — for carb cycling or calorie cycling plans, label each day (e.g., "High Day — 2,400 kcal" vs "Low Day — 1,800 kcal") and color-code the day header accordingly.

Additional Views / Sections

• Shopping list tab — aggregated by store section (Proteins, Produce, Grains/Pantry, Dairy, Frozen), with quantities rounded to purchasable units. Checkboxes for each item.
• Prep guide tab — Sunday prep timeline as a visual step-by-step with estimated times.
• Macro dashboard — summary panel showing weekly averages vs targets: avg daily kcal, protein g/kg, fiber g, and a simple bar chart comparing planned vs target.
• Training schedule — if fitness plan is included, show as a sidebar or separate tab with day-by-day exercises.

UI/UX Requirements

• Clean, appetizing design — warm color palette, rounded cards, readable portions
• Mobile-responsive — stack day columns vertically on mobile
• Click to expand — meal cards expand on click to show full ingredient list, cooking notes, and nutrition detail
• Print-friendly — @media print stylesheet that renders the week view cleanly on paper

Data Architecture

Embed all plan data as JSON in the app:

interface MealPlan {
  weeks: Week[];
  profile: { goal: string; tdee: number; target_kcal: number; macros: Macros };
  shoppingList: ShoppingSection[];
  prepGuide: PrepStep[];
}

interface Week {
  label: string;  // "Week 1", "High Carb Cycle", etc.
  days: Day[];
}

interface Day {
  name: string;  // "Monday"
  label?: string; // "High Day", "Rest Day", etc.
  target_kcal: number;
  meals: Meal[];
}

interface Meal {
  slot: 'breakfast' | 'lunch' | 'dinner' | 'snack' | 'pre-bed';
  name: string;
  items: { food: string; portion: string; }[];
  macros: Macros;
  alternatives?: Meal[];  // swap options
}

interface Macros { protein: number; carbs: number; fat: number; fiber: number; kcal: number; }

Best Practices

1. Adherence beats optimization — a 90%-adhered B+ plan beats a 50%-adhered A+ plan. Build around foods the user already likes.
2. Protein is the anchor macro — set it in g/kg first, then fill carbs/fat by preference.
3. Budget a 10% flex buffer — plans that forbid all unplanned food get abandoned.
4. Re-calculate TDEE after weight changes ~5 kg — BMR shifts with body mass.
5. Track for 2 weeks before adjusting — daily weight fluctuates ±1–2 kg from water/glycogen/gut contents. Use a 7-day rolling average.

Limitations

• Nutritional values are estimates (±10–15% even with USDA data — portion eyeballing adds more error)
• TDEE formulas are population averages with ~10% individual error — real-world tracking over 2–3 weeks is the only way to find someone's true maintenance
• Not a substitute for a registered dietitian, especially for medical conditions, disordered eating history, or pregnancy
• Training templates are generic — modify around injuries and individual response