PARI

def _dietary(resp):
    ranks = {g: _FREQ_RANK.get(resp.get(g, "Never"), 0)
             for g, _ in FOOD_GROUPS}

    # Diversity: groups eaten >=3 days/week (rank >= 2)
    diversity = sum(1 for g, _ in FOOD_GROUPS if ranks[g] >= 2)
    if   diversity >= 6: div_pts = 0
    elif diversity >= 4: div_pts = 7
    elif diversity >= 2: div_pts = 14
    else:                div_pts = 20

    # Protein: best weekly frequency among protein-dense groups
    pmax = max(ranks[g] for g in PROTEIN_GROUPS)
    prot_pts = {3: 0, 2: 5, 1: 10, 0: 15}[pmax]

    return div_pts + prot_pts, {...}

The dietary domain. Counts how many food groups a student eats at least three days a week, and how often they eat protein-dense foods. Less variety and less protein add more risk points.

def baz(weight_kg, height_cm, age_years, sex):
    """Return (baz, bmi, category)."""
    b   = bmi(weight_kg, height_cm)
    row = _nearest_row(sex, age_years)
    if b is None or row is None:
        return None, None, None
    _, L, M, S = row
    if L == 0:
        z = math.log(b / M) / S
    else:
        z = (((b / M) ** L) - 1) / (L * S)
    return round(z, 2), round(b, 1), _category(z)

BMI-for-age z-score. Uses the WHO LMS method to convert a student’s BMI into a z-score for their age and sex. A score below −2 means underweight.