# Fiber Intake Guidance

Default formula: **14 g per 1,000 kcal**, with goal-specific caps, floors, and overrides below.

## Universal Floors and Ceilings

- Floor: 25 g/day women, 30 g/day men
- Soft ceiling: 45 g/day (GI tolerance)
- Distribution: ~7 g per main meal, ~3 g per snack
- Whole foods first; supplements as adjuncts only

## Goal-Specific Targets

| Goal | Target | Notes |
|---|---|---|
| Bulking (≥3,500 kcal) | 35–45 g/day | Do NOT scale to 56–63 g. Use refined carbs (white rice, white potato, juice, bread) to fill kcal without GI volume. Include ~2 g/day β-glucan (40–50 g oats covers it). |
| Fat loss / deficit | 30–38 g/day | Do NOT scale down with calories. Bias viscous fibers (psyllium, β-glucan, glucomannan, legumes). Cap if crowding protein. |
| Body recomp | 30–35 g/day baseline; 35–40 g on training days | Distribute and time as for fat loss. |
| General health | 30–38 g/day | Standard formula applies. |

## Per-Training Overrides

- **Pre-training (2–3 h before resistance training):** ≤5 g fiber in that meal
- **Carb loading / combat sports cut:** <10 g/day for max 4 days during cut window only
- **Active GI disease flare (IBD, IBS, diverticulitis):** lower-fiber or FODMAP-modified plan; do not apply standard targets

## Source Priority

### Whole foods (primary)
- Legumes: 7–8 g per ½ cup cooked
- Oats: ~4 g per 40 g (also β-glucan source)
- Berries: raspberries 8 g/cup
- Vegetables: broccoli 5 g/cup; leafy greens; Brussels sprouts
- Whole grains: wholegrain bread 2–3 g/slice; brown rice; quinoa
- Fruit with skin: pear 5 g; apple 4 g
- Nuts/seeds: chia 4 g/tbsp; ground flax 2 g/tbsp; almonds 12.5 g/100 g

### Supplements (adjuncts)
- Psyllium: 5–10 g, 1–3× daily before meals. Best for satiety, LDL, glycemia.
- β-glucan: ≥3 g/day for cholesterol benefit
- Inulin/FOS: prebiotic but high gas; tolerance cap ~10 g/day
- Methylcellulose: laxation only, no gas

## Adjustment Triggers

| Trigger | Action |
|---|---|
| New user currently <20 g/day | Ramp ~5 g/day every 1–2 weeks; never +10 g above habitual; ensure ≥2 L/day fluids |
| Persistent bloating / GI distress >2 weeks | Drop fiber 5 g/day at a time toward floor |
| Bulker missing kcal targets due to early satiety | Drop fiber 5 g/day toward 30 g floor; swap fibrous carbs for refined |
| Constipation | Increase fiber and fluids |
| Elevated LDL | Add 5–10 g/day psyllium in divided doses before meals; hit ≥3 g/day β-glucan |
| Pre-diabetes | Upper end of target with viscous fibers |
| FODMAP sensitivity (symptoms on onion, garlic, wheat, legumes, apples/pears/mangoes) | Substitute: oats, kiwifruit, carrots, berries, rice, quinoa, firm bananas |
| Carb load / weight cut | Drop <10 g/day for max 4 days |

## Tolerance Thresholds

| Total daily fiber | Typical response |
|---|---|
| <25 g | Symptom-free for most |
| 25–40 g | Symptom-free if introduced gradually |
| ~50 g | Gas, bloating, altered bowel habits common |
| ~70 g | Pronounced symptoms; potential mineral malabsorption |

Specific supplement ceilings: Inulin/FOS ~10 g/day; GOS ~12 g/day; Psyllium up to ~30 g/day; Resistant maltodextrin ~40 g/day.

## Operating Principles

- Cap fiber at high calories (bulks); preserve absolute grams at low calories (cuts)
- Total kcal and protein dominate; fiber is a secondary lever
- Adherence and source diversity matter more than soluble/insoluble ratios

For full citations see https://json.fit/fiber-references.md