Kosher: thousands of years of food law, not a health label.
Kosher food follows Jewish dietary law: which animals, how they're slaughtered, and keeping meat and dairy apart. Here's how it works in practice, in Singapore and the DACH countries, and why "kosher" on a pack says nothing about calories.
The short version
- What it is
- Jewish dietary law (kashrut): permitted animals only, ritual slaughter, no blood, meat and dairy kept strictly apart, extra rules for wine and Passover.
- Good for
- Living your faith and your tradition. It isn't a health or weight-loss plan, and was never meant to be.
- Bad at
- Nothing to judge. Kosher tells you a food is permitted, not that it's good for you.
- Evidence
- Not applicable. A faith practice, not a health diet.
- Our take
- Your rabbi decides what's kosher. We make sure your plan never asks you to break the rules you keep.
What kosher food actually is
"Kosher" means fit or proper. The laws come from the Torah and from the oral law later written down in the Talmud, and rabbis have interpreted and extended them over the centuries to cover new foods and technologies.2 They deal mainly with three things: which animals are allowed, the ban on blood, and keeping meat and milk apart.2
The Torah allows land animals that have split hooves and chew the cud, and water animals with fins and scales.1 So beef, lamb, goat and traditional poultry are in; pork, rabbit, shellfish and fish without scales, like catfish and shark, are out.2 The separation of meat and milk goes back to the verse "you shall not boil a kid in its mother's milk".1
Practice varies a lot. Orthodox Jews generally follow the laws strictly, Conservative Jews follow them with some leniencies, and many Reform Jews don't treat them as essential.2 Customs differ between Ashkenazi and Sephardi communities too, for example on which foods are allowed at Passover.2 Rabbis and the communities that follow them, not Healthen, decide what is kosher.
Singapore: the Jewish community is small, and the Jewish Welfare Board lists a single kosher shop as the only place in the country to buy kosher meat, chicken and milk. Many packaged kosher products are on the shelves at mainstream supermarkets.6
Germany, Austria, Switzerland: the Orthodox Rabbinical Conference of Germany publishes a searchable list of more than 4,500 kosher foods and drinks, many of them ordinary supermarket brands.5 Kosher slaughter is done without stunning.2 Germany allows that only with an exemption for religious communities,3 and Switzerland bans it for mammals but explicitly allows kosher and halal meat to be imported.4
How it works in your body
Straight answer: kashrut has no metabolic mechanism. It isn't low-carb, low-fat or anything else. Its purpose is religious, and the rules don't need a health explanation to be valid for the people who keep them.2
What it does change on your plate: no pork and no shellfish, so protein comes from beef, lamb, chicken, kosher fish, eggs, dairy and legumes. Meat meals are free of dairy, so no butter on the steak and no cheese on the burger. After eating meat, many people wait before eating dairy, anywhere from three to six hours depending on family custom; after most dairy, the wait is much shorter.2 Meat is soaked and salted to draw out blood before it is cooked, usually by the butcher.2
Everything else, from a vegetable stew to a doughnut, can be kosher. The rules don't choose between them.
What you eat, what you don't
Eat
- Beef, lamb, goat, chicken, turkey, duck, from kosher slaughter
- Fish with fins and scales: salmon, carp, trout, cod, tuna, herring
- Eggs, which are "pareve" (neutral) and go with meat or dairy
- Dairy with kosher supervision, eaten separately from meat
- Vegetables, fruit, grains, legumes, nuts, checked for insects where needed
- Wine and grape juice made under kosher supervision
Not eaten
- Pork, rabbit, horse and other non-kosher animals
- Shellfish and fish without scales: prawns, crab, mussels, squid, catfish, eel
- Blood, and certain fats and parts of permitted animals
- Meat and dairy together, in the same dish or meal
- Insects, and ingredients like carmine (red colour from insects)
- Leavened grain products during Passover
Alcohol and kosher
Alcohol isn't forbidden. Wine plays a part in Jewish ritual, and the rules for it are strict: grape products count as kosher only if Sabbath-observing Jews handle them from pressing to bottling, unless the wine is heat-treated ("mevushal").2 Many beers and spirits also carry kosher certification; the German kosher list includes spirits.5
What the rules don't do is say how much is healthy. On that, our view is the same as for everyone: the WHO says there is no level of drinking that is safe for health.8 All the details are in our alcohol guide.
What the research says
Kosher is a faith practice, and research on it as a "diet" barely exists. What we can say is what science shows about the claims people stick on it, and about some foods inside the rules.
Kosher laws are not health laws
Food scientists who have worked with kosher supervision for decades are clear: the laws are understood by the community as given without needing an explanation, and the health justifications were added only in modern times.2 The popular pork-and-trichinosis argument is weak, because any meat can carry germs and thorough cooking is what protects you.2
Deli meat is still processed meat
The WHO's cancer agency classifies processed meat as carcinogenic to humans, mainly for bowel cancer, with each 50 g eaten daily linked to an 18% higher risk.7 Kosher salami, pastrami and hot dogs are processed meat too. The hechsher (kosher mark) settles the religious question, not this one.
Kosher labels help some people with allergies, but not all
Many people with milk allergy or lactose intolerance use "pareve" labels as a first screen. That's reasonable, with limits. Kosher law can disregard tiny accidental traces, and pareve foods made on dairy equipment have caused reactions in very sensitive people.2
The uncomfortable truth
"Kosher means healthier and cleaner." No. Kosher means permitted under Jewish law. Kosher-certified sweets, crisps and soft drinks exist in every supermarket, and they behave exactly like the uncertified versions once they hit your blood sugar. The food industry knows a trust mark sells, and it's happy to let you read "healthy" into it.
"Pareve means dairy-free, so it's safe for my milk allergy." Religiously, yes. Medically, not always. Pareve products made on shared lines can carry traces of milk that are allowed under kosher law but still enough to trigger a reaction.2 If your allergy is severe, check the EU allergen label, not just the hechsher.
The risks
Kashrut itself carries no health risk. The practical risks come from what sits inside the rules.
- Hidden milk in "pareve". Traces from shared equipment can matter for severe allergies.2 Read the allergen list every time.
- Processed meat. Deli meats are part of many food traditions. Keep them occasional.7
- Shabbat and holiday wine. Ritual wine is one thing; a bottle a night is another. Alcohol has no safe level for health.8
- Limited choice. In Singapore, kosher meat and milk come from very few outlets.6 That can push meals towards bread, pasta and packaged food. Fish, eggs and legumes help keep protein up.
- Fasting days. Some Jewish holidays, like Yom Kippur, are fast days. If you take medication, especially for diabetes, ask your doctor how to handle it.
Allergies: watch the staples
Several classic kosher foods are built on major allergens. If you're allergic, the plan swaps them, and the swap stays kosher.
| Kosher staple | Allergen (EU list of 14)9 | Swap |
|---|---|---|
| Challah, bagels, matzo | Cereals containing gluten (challah also eggs, often sesame) | Gluten-free bread, potatoes, rice |
| Gefilte fish, lox, herring | Fish (gefilte fish also eggs) | Chicken, eggs, lentils |
| Cream cheese, blintzes, cheesecake | Milk | Avocado, pareve spreads checked for traces |
| Hummus, tahini, sesame-topped bread | Sesame | White bean dip with olive oil |
| Kugel, shakshuka, egg challah | Eggs | Roast vegetables, chickpea-flour bakes |
| Almond macaroons, nut-based Passover cakes | Tree nuts | Coconut macaroons, fruit |
| Pareve margarine, soy milk, tofu | Soy | Olive oil, oat milk (outside Passover) |
Talk to your doctor before changing how you eat if you…
- keep fast days and take insulin or similar diabetes medication
- are pregnant or breastfeeding
- have kidney disease
- have a severe food allergy and rely on kosher labels to avoid it
- have ever had an eating disorder
- are under 18
Healthen me asks about all of these and gives you a different plan if any apply.
How we use kosher food rules in your plan
Kosher is a filter in our engine. Tick it in Healthen me and the plan removes pork, shellfish, non-kosher fish and blood products, and it never puts meat and dairy in the same meal. Recipes are adapted, not just deleted: the cream sauce on the chicken becomes olive oil, lemon and herbs; the prawn salad becomes salmon. Meals are labelled meat, dairy or pareve, and the plan spaces meat and dairy meals apart.
Our fast fits: water, black coffee and green tea. If you keep fast days, tell Healthen me and the plan works around your calendar.
What we can't do: tell you whether a product, butcher or restaurant is kosher, or which supervision to trust. That's for you, your rabbi and your community, using marks and lists like the ORD list in Germany or the Jewish Welfare Board in Singapore. Many households also keep other rules at the same table, like halal or vegetarian, and the filters stack.
This article is general information, not medical or religious advice. For questions of Jewish law, ask a rabbi you trust; for health questions, talk to your doctor.
Sources
- The Torah: Leviticus 11:3 and 11:9 (permitted animals and fish); Exodus 23:19 (meat and milk). sefaria.org/Leviticus.11, sefaria.org/Exodus.23.19
- Regenstein JM, Chaudry MM, Regenstein CE. The kosher and halal food laws. Comprehensive Reviews in Food Science and Food Safety 2003;2(3):111–127. doi.org/10.1111/j.1541-4337.2003.tb00018.x
- Germany. Tierschutzgesetz (Animal Welfare Act), § 4a: slaughter only after stunning; exemptions for religious communities. gesetze-im-internet.de/tierschg/__4a.html
- Switzerland. Animal Welfare Act of 16 December 2005 (SR 455), Art. 14 (import of kosher and halal meat) and Art. 21 (stunning before slaughter). fedlex.admin.ch/eli/cc/2008/414/en
- Orthodoxe Rabbinerkonferenz Deutschland (ORD). Koscherliste. ordonline.de/koscherliste
- Jewish Welfare Board Singapore. Travel info: kosher food. singaporejews.com/travel-info
- Bouvard V et al. Carcinogenicity of consumption of red and processed meat. The Lancet Oncology 2015;16(16):1599–1600. doi.org/10.1016/S1470-2045(15)00444-1
- Anderson BO et al. Health and cancer risks associated with low levels of alcohol consumption. The Lancet Public Health 2023;8(1):e6–e7. doi.org/10.1016/S2468-2667(22)00317-6
- Regulation (EU) No 1169/2011 on food information to consumers, Annex II (the 14 allergens). eur-lex.europa.eu/eli/reg/2011/1169/oj