Absorption & Bioavailability
What PlateBreaker accounts for in nutrient absorption and current limitations due to data gaps.
What is Bioavailability?
Section titled “What is Bioavailability?”Bioavailability is the proportion of a nutrient that your body can actually absorb and use from food.
The key concept:
- 100mg of iron in spinach ≠ 100mg of absorbed iron
- Nutrients in food ≠ nutrients used by your body
- Cooking, food combinations, and individual factors all affect bioavailability
What We Account For
Section titled “What We Account For”1. Cooking Methods & Nutrient Retention
Section titled “1. Cooking Methods & Nutrient Retention”PlateBreaker applies USDA retention factors when cooking methods change nutrient content:
Nutrient losses from cooking:
- Water-soluble vitamins (B vitamins, vitamin C) decrease with boiling
- Fat-soluble vitamins mostly retained, but some loss with high heat
- Minerals generally stable, but can leach into cooking water
Examples:
- Raw spinach → boiled spinach: ~50% vitamin C loss
- Raw carrots → steamed carrots: minimal nutrient loss
- Raw chicken → baked chicken: B vitamin reduction
How it works:
- Each ingredient has a cooking method tag
- Retention factors apply automatically
- Nutrition calculations reflect cooked values
2. Individual Amino Acid Calculations
Section titled “2. Individual Amino Acid Calculations”Instead of using average protein values, PlateBreaker calculates each amino acid separately:
How this works:
- Different proteins have different amino acid profiles
- Wheat is low in lysine; legumes are low in methionine
- PlateBreaker tracks each amino acid individually
Example:
- 20g protein from chicken: complete amino acid profile
- 20g protein from rice: low lysine, adequate other amino acids
- Result: PlateBreaker shows lysine gap even if total protein is met
Current Limitations
Section titled “Current Limitations”Due to incomplete research data, PlateBreaker cannot yet account for:
1. Variable Amino Acid Bioavailability
Section titled “1. Variable Amino Acid Bioavailability”The issue:
- Some amino acids are absorbed more efficiently from certain foods
- Animal proteins: 90-95% digestibility
- Plant proteins: 70-90% digestibility
- Anti-nutritional factors (phytates, tannins) reduce absorption
Why we can’t account for it:
- Limited comprehensive research data across all foods
- High variability between individuals
- Depends on gut health, food preparation, and combinations
Impact: Amino acid intake may be overestimated, especially for plant-based diets.
2. Mineral Bioavailability Differences
Section titled “2. Mineral Bioavailability Differences”The issue:
- Heme iron (meat): 15-35% absorbed
- Non-heme iron (plants): 2-20% absorbed
- Calcium from dairy vs. plants varies significantly
- Zinc from animal sources more bioavailable than plants
Why we can’t account for it:
- USDA data doesn’t distinguish heme vs. non-heme for all foods
- Absorption affected by other nutrients in the meal (enhancers/inhibitors)
- Individual variation in absorption capacity
Impact: Mineral intake may be overestimated for plant-heavy diets.
3. Vitamin Absorption Factors
Section titled “3. Vitamin Absorption Factors”The issue:
- Fat-soluble vitamins (A, D, E, K) require dietary fat for absorption
- B12 requires intrinsic factor (some individuals lack this)
- Folate form matters (synthetic folic acid vs. natural folate)
Why we can’t account for it:
- Requires knowing all foods consumed together in a meal
- Individual factors (age, gut health, medications) vary widely
- Data on co-consumed nutrients needed
Impact: Actual absorbed amounts may differ from calculated amounts.
4. Anti-Nutritional Factors
Section titled “4. Anti-Nutritional Factors”The issue:
- Phytates (grains, legumes): reduce mineral absorption (iron, zinc, calcium)
- Oxalates (spinach, rhubarb): reduce calcium absorption
- Tannins (tea, coffee): reduce iron absorption
- Protease inhibitors (raw legumes): reduce protein digestion
Why we can’t account for it:
- Anti-nutrient content varies by food preparation
- Soaking, fermenting, and cooking reduce anti-nutrients (but data is incomplete)
- Effects depend on overall diet composition
Impact: Mineral and protein absorption from plant foods may be lower than calculated.
5. Nutrient Interactions
Section titled “5. Nutrient Interactions”The issue:
- High calcium inhibits iron absorption
- Vitamin C enhances iron absorption
- Vitamin D enhances calcium absorption
- Zinc competes with copper for absorption
Why we can’t account for it:
- Requires analyzing all foods consumed together
- Complex interactions across multiple meals
- Individual variation in response
Impact: Single-nutrient focus may miss interaction effects.
Future Improvements
Section titled “Future Improvements”As research data becomes more comprehensive, PlateBreaker aims to incorporate:
- Heme vs. non-heme iron distinction
- Protein digestibility scores (DIAAS)
- Anti-nutrient content and effects
- Food pairing recommendations for better absorption
Until then: Use PlateBreaker’s calculations as a guide, but remember they may overestimate bioavailable amounts for certain nutrients, especially in plant-heavy diets.