Dulce de leche: browned, sweet and never studied in people

Nobody has run a study on people eating dulce de leche. The closest trials fed healthy boys aged 11 to 14 a diet rich in browning reaction products from fried, baked and toasted foods. In 18 of them, 2 weeks on that diet lowered iron bioavailability about 2.7-fold compared with a low-browning diet, while blood iron markers did not change. Dulce de leche is a browned milk food, so these trials show the direction for browning products and give no size for a spoonful of this spread. On the same kind of diet apparent nitrogen absorption fell 12% and protein digestibility 6%, and calcium absorption held near 40%, at 40.4% against 38.2%. As a food, USDA lists dulce de leche at 55.35 g carbohydrate, 6.84 g protein, 251 mg calcium and 4.5 g saturated fat per 3.5 oz (100 g). That is one record with no sample spread, and real products vary with how much sugar the recipe uses.

The numbers, per 3.5 oz (100 g)

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• USDA lists dulce de leche at 55.35 g carbohydrate and 6.84 g protein per 3.5 oz (100 g), with 251 mg calcium and 4.5 g saturated fat. — USDA FoodData Central SR Legacy record Dulce de Leche, FDC 173461 (n = 1 record) Evidence E source
  Per 100 g: carbohydrate 55.35 g, protein 6.84 g, saturated fat 4.534 g, calcium 251 mg, phosphorus 193 mg, riboflavin 0.405 mg, vitamin B12 0.31 micrograms

What a real portion looks like

• In the US survey food database an unspecified serving of dulce de leche is set at 150 g and a cup at 300 g. — FNDDS food code 13252200, Dulce de leche, WWEIA category Pudding (n = 2 portion measures) Evidence E source
  Quantity not specified 150 g; 1 cup 300 g

What your body absorbs

• In a 2-week crossover trial in 18 boys aged 11 to 14, a diet rich in browning reaction products lowered iron bioavailability about 2.7-fold compared with a low-browning diet. — 18 healthy adolescent males aged 11-14, 2 weeks per diet (n = 18) Evidence B source
  Iron fecal excretion about 1.4-fold higher and iron bioavailability about 2.7-fold lower on the brown diet; serum iron markers unchanged
• The same kind of browning-rich diet cut apparent nitrogen absorption by 12% and protein digestibility by 6% in 18 adolescent boys over 2 weeks. — 18 healthy adolescent males aged 11-14, 2 weeks per diet with 40-day washout (n = 18) Evidence B source
  Fecal nitrogen +47%, apparent nitrogen absorption -12%, nitrogen digestibility -6%; nitrogen retention not significantly different
• Calcium absorption did not change on a browning-rich diet in 18 adolescent boys, staying near 40% over 2 weeks. — 18 male adolescents, 2 weeks per diet (n = 18) Evidence B source
  Calcium bioavailability 40.4 +/- 5.1% on low-browning vs 38.2 +/- 3.6% on browning-rich diet
• In 20 boys aged 11 to 14, two weeks on a browning-rich diet reduced apparent and fractional phosphorus absorption compared with a low-browning diet. — 20 healthy male adolescents aged 11-14, 2 weeks per diet with 40-day washout (n = 20) Evidence B source
  Apparent phosphorus absorption lower (P = 0.03) and fractional absorption lower (P = 0.04); serum phosphorus unchanged

What cooking and storage change

• In laboratory batches of dulce de leche, a lower cooking temperature cut the heat marker HMF by 35% in a lactose-free recipe, and swapping half the sucrose for tagatose cut it by up to 80%. — laboratory-scale dulce de leche made from whole, skimmed or lactose-free milk cooked at 110 to 130 C, compared with 3 commercial products Evidence D source
  HMF down 35% with lower process temperature in lactose-free formula; down up to 80% with 50% tagatose in place of sucrose, with pH, color and viscosity unchanged
• Lactose-free dulce de leche browned much harder in testing, with free HMF of about 134 micromol per liter against about 28 in the traditional version, and came out firmer. — experimental batches of homogenized lactose-free and traditional dulce de leche (n = 4 treatments) Evidence D source
  Free HMF 133.77 +/- 3.42 vs 28.45 +/- 1.16 micromol per liter; hardness 1611 vs 437 g

Who this works differently for

• A review of Indonesian data concluded that sweetened condensed milk, the base of dulce de leche, should not be given to children aged 1 to 3 as a milk for growth because of its high sugar and limited nutrition. — young Indonesian children aged 1-3, review of existing studies Evidence C source
  No study measured long-term health effects; advice rests on sugar content

The bottom line

In a fourth trial, 20 boys on the browning-rich diet absorbed less phosphorus, and the abstract reports only that the drop was significant (P = 0.03), with no size. The US survey database files dulce de leche under pudding and sets an unspecified serving at 150 g and a cup at 300 g. A spread on toast is far smaller, so what a portion carries depends on how you use it. Cooking decides how much of the heat marker HMF forms, and the lactose-free version browns hardest. In laboratory batches, lactose-free dulce de leche had free HMF of about 134 micromol per liter against about 28 in the traditional recipe, and it came out firmer. Lowering the cooking temperature cut HMF by 35% in a lactose-free recipe. Replacing half the sucrose with tagatose cut it by up to 80% without changing pH, color or thickness. These are food chemistry results with no human exposure or health outcome measured. For small children, a review of Indonesian data concluded that sweetened condensed milk, the base of dulce de leche, should not be given to children aged 1 to 3 as a milk for growth because of its high sugar and limited nutrition. That advice is about condensed milk drunk as milk, and the authors say no study has measured long-term health effects. Dulce de leche is made from milk, and we found no study on milk allergy, lactose intolerance, contamination or poisoning from dulce de leche itself, so this page has no safety section.

Sources

1. dlch-r1-01 · USDA FoodData Central SR Legacy, dataset
   Dulce de Leche (FDC 173461, SR Legacy, Dairy and Egg Products): carbohydrate 55.35 g; protein 6.84 g; saturated fat 4.534 g; calcium 251 mg; phosphorus 193 mg; riboflavin 0.405 mg; vitamin B12 0.31 ug per 100 g; no Foundation record, no sample spread
   USDA FoodData Central, SR Legacy, FDC 173461 · checked 2026-09-28
2. dlch-r1-02 · USDA FNDDS 2021-2023, dataset
   Dulce de leche (FNDDS 13252200, FDC 2705699, WWEIA Pudding): 1 cup 300 g; Quantity not specified 150 g
   USDA FNDDS 2021-2023, food code 13252200 (FDC 2705699) · checked 2026-09-28
3. dlch-r1-05 · randomized crossover trial
   In the human assay 18 healthy adolescent males (11-14 years) participated in a 2-wk randomized two-period crossover trial. ... The BD consumption increased iron fecal excretion ( approximately 1.4-fold) and significantly decreased its bioavailability ( approximately 2.7-fold), mainly due to the effects found at digestive level.
   Mol Nutr Food Res, 2009 · checked 2026-09-28
4. dlch-r1-06 · randomized crossover trial
   Compared with consumption of the WD, consumption of the BD resulted in 47% higher fecal nitrogen fecal excretion (P = 0.002), 12% lower apparent nitrogen absorption (P = 0.000), and a 6% lower nitrogen digestibility (P = 0.000).
   Am J Clin Nutr, 2006 · checked 2026-09-28
5. dlch-r1-07 · randomized crossover trial
   In accordance, calcium bioavailability in adolescents did not vary between the diets (%WD = 40.4 +/- 5.1, %BD = 38.2 +/- 3.6).
   J Agric Food Chem, 2009 · checked 2026-09-28
6. dlch-r1-08 · randomized crossover trial
   A tendency to increase daily phosphorus fecal excretion was observed subsequent to the brown diet consumption compared with the white diet (P = 0.10), which led to significant reductions in phosphorus apparent absorption (P = 0.03) and fractional absorption (P = 0.04).
   Nutrition, 2011 · checked 2026-09-28
7. dlch-r1-03 · food science experiment
   HMF formation in DL was mitigated (35%) in a lactose-free formulation by lowering the process temperature. Moreover, HMF formation was reduced up to 80% replacing sucrose by tagatose without affecting the quality parameters (pH, soluble solids, colour, and apparent viscosity).
   Food Additives and Contaminants Part A, 2021 · checked 2026-09-28
8. dlch-r1-04 · food science experiment
   The main results show that the homogenized lactose-free DL obtained a higher concentration of free 5-Hydroxymethylfurfural (HMF) (133.77 ± 3.42 μmol l-1). ... (28.45 ± 1.16 μmol l-1 free HMF, 437.17 ± 279.3 g hardness, and 406.20 ± 311.69 g gumminess).
   Journal of Dairy Research, 2021 · checked 2026-09-28
9. dlch-r1-09 · review
   Considering its limited nutritional value and high sugar content, sweetened condensed milk (SCM) should not be administered to young children (1-3 years old) with the goal of promoting their growth and development. ... Conclusive scientific evidence is also still lacking regarding the health risks of long-term SCM consumption by young Indonesian children at early ages, as no study has focused on this specific topic.
   Asia Pac J Clin Nutr, 2020 · checked 2026-09-28