Lamb vs mutton: calories compared

We hold no card on the age line between lamb and mutton. The table sets broiled ground lamb against roasted mutton, so cut and cooking differ too. For health, the World Health Organization counts both as red meat, and its cancer agency places red meat in Group 2A, probably carcinogenic to humans.

In 36 women living in convents, lamb three times a week for 5 weeks left cholesterol and triglycerides unchanged, no different from chicken. The single USDA record for roasted Navajo mutton lists 4.44 mcg of vitamin B12 per 3.5 oz (100 g), and in absorption studies a 3.0 mcg dose eaten as mutton was 83% absorbed.

In pooled case-control studies, raw or undercooked sheep meat carried 3.85 times the odds of acute toxoplasma infection, and the authors advise pregnant women and other at-risk groups to avoid it. USDA FSIS advises 145 °F (63 °C) with a 3-minute rest for lamb steaks, chops and roasts, and 160 °F (71 °C) for uncooked sausages with ground lamb. We hold no FSIS figure for plain ground lamb.

Alpha-gal syndrome, an allergy to mammalian meat, can bring on anaphylaxis one to several hours after eating. At one Turkish center, 64% of 37 children with red meat allergy had anaphylaxis on exposure. Choose by the dish, and cook either to temperature.

Evidence behind this note

1. Level E The WHO counts pork as red meat alongside beef, veal, lamb, mutton, horse and goat. World Health Organization, Cancer: Carcinogenicity of the consumption of red meat and processed meat, Q&A
2. Level E WHO places red meat, which by its own definition includes lamb, in IARC Group 2A, probably carcinogenic to humans. WHO, Cancer: Carcinogenicity of the consumption of red meat and processed meat
3. Level B Swapping lean lamb for lean chicken three times a week for five weeks left total cholesterol, LDL and triglycerides unchanged in 36 women. Br J Nutr, 2012
4. Level E Roasted mutton in the USDA reference table gives 4.44 mcg vitamin B12, 38 mcg selenium and 33.43 g protein per 3.5 oz (100 g). USDA SR Legacy, Mutton, cooked, roasted (Navajo), fdc_id 167634
5. Level C In a systematic review of vitamin B12 absorption, a 3.0 mcg dose eaten as mutton was absorbed at 83%, against 4.5% for a 38 mcg dose from liver. Ann Nutr Metab, 2013
6. Level C Across case-control studies, eating raw or undercooked sheep meat carried odds of acute toxoplasma infection of 3.85, and the authors advise at-risk groups, including pregnant women, to avoid it. Crit Rev Food Sci Nutr, 2018
7. Level E USDA FSIS advises cooking raw lamb steaks, chops and roasts to at least 145 °F (63 °C) and letting the meat rest for at least three minutes before carving or eating. USDA FSIS, Doneness Versus Safety
8. Level E USDA FSIS advises cooking uncooked sausages made with ground pork, beef, lamb or veal to 160 °F (71 °C), and those made with ground turkey or chicken to 165 °F (74 °C). USDA FSIS, Sausages and Food Safety
9. Level C Alpha-gal syndrome, an allergy to mammalian meat including lamb, gave urticaria to 63.8% and at least one gut symptom to 69.2% of 1162 patients pooled from 15 studies, with onset an hour or more after eating in 91.8%. Neurogastroenterol Motil, 2026
10. Level E A US gastroenterology practice update warns that the same allergy can cause anaphylaxis one to several hours after mammalian meat, which is why it is missed. Clin Gastroenterol Hepatol, 2023
11. Level C Among 37 Turkish children with red meat allergy, 64% had anaphylaxis on exposure and most were sensitized to both mutton and beef. Turk J Pediatr, 2021

Written from the studies and agency guidance we hold for both foods, reviewed by the Bioma editorial system. How we verify.

Read more about these foods

• Lamb: how the animal was fed shows up in your blood
• Mutton: dense in B12, and most trials used lamb

Rankings and guides

• Calories: what it does and what the evidence shows
• Which foods give the most protein for the fewest calories?
• Dietary fat: what it does and how much you need

More comparisons

• Lamb vs beef
• Lamb vs chicken
• Lamb vs goat
• Lamb vs pork
• Mutton vs beef
• Mutton vs chicken

• Lamb: USDA FoodData Central, Lamb, ground, cooked, broiled, FDC ID 172544 · all forms of lamb
• Mutton: USDA FoodData Central, Mutton, cooked, roasted (Navajo), FDC ID 167634 · all forms of mutton

Each food is one USDA entry, chosen as it is usually eaten. Other cuts, brands and preparations differ, and the links show them. % DV uses FDA Daily Values for adults. How we verify.