What it does in the body
- Energy source (hepatic metabolism)
- Natural sweetener in fruits (promotes fruit consumption for other nutrients)
- Glycogen replenishment (liver glycogen preferentially)
- Flavor enhancement in natural foods
How much you need (Daily Value)
| Group | Recommended | Source |
|---|---|---|
| Adult male | No RDA; limit added fructose to <25g/day (AHA). Fruit fructose typically 15-20g/day is safe | AHA/WHO |
| Adult female | No RDA; limit added fructose to <25g/day | AHA/WHO |
| Pregnancy | Limit added fructose; moderate fruit intake encouraged | WHO |
| Children | Limit added sugars to <25g/day total | AHA |
| Older adults | Same as adults; monitor for metabolic syndrome risk | AHA |
Richest food sources
| Food | Amount | Where |
|---|---|---|
| Honey | 40g fructose per 100g | global |
| Agave nectar | 56g fructose per 100g | mesoamerica |
| Apple | 6g fructose per 100g | global |
| Mango | 4.7g fructose per 100g | south-asia |
| Dates (dried) | 32g fructose per 100g | middle-east |
| Grapes | 8.1g fructose per 100g | global |
| Jackfruit | 9.5g fructose per 100g | southeast-asia |
| Watermelon | 3.4g fructose per 100g | global |
If you don't get enough
Mild: No clinical deficiency — fructose is not essential
Moderate: Not applicable — glucose can fulfill all energy needs
Severe: Not applicable
Time to onset: Not applicable — fructose deficiency does not occur
Too much
Upper limit: WHO recommends <10% of calories from free sugars (~50g/day total added sugars). Fructose-specific concern begins >50g/day from added sources
NAFLD, elevated triglycerides, insulin resistance, hyperuricemia and gout, visceral fat accumulation, metabolic syndrome
How well you absorb it
Absorbed via GLUT5 transporter in small intestine; capacity ~25-50g per sitting (varies individually). Excess causes malabsorption, bloating, diarrhea
Helped by: Glucose co-ingestion (improves fructose absorption via GLUT2 activation), Gradual intake (allows transporter upregulation)
Hindered by: Fructose malabsorption (affects ~30-40% of people at doses >25g), Sorbitol (competes for GLUT5)
Cooking & storage
Heat-stable at cooking temperatures. Caramelizes at lower temperature than glucose, creating browning and flavor. High-fructose corn syrup in processed foods is the primary concern, not naturally occurring fructose in cooked whole foods.
Nutrisize Health totals every nutrient from what you actually eat, against targets set for your age and sex, and flags what's short — across 4,995 foods, on your device.
