Some foods are explicitly Haram in Islam.
Any living being blood
Alcohol
Non-permissible animals – Pork
Animal blood and by-products & the decaying flesh of dead animals
Human-derived ingredients
Protein/ Enzymes, etc., extracted from Haram animals
While seafood falls in the Halal food category, some species are considered Haram. Like Hanafi's school of thought believes shellfish is haram.
Likewise, meat, milk, other dairy products, eggs, dairy cheese, and others are Halal. However, if the animals (cows/chickens, etc.) eat pork feeds or have not been slaughtered according to Zabiha rules will be Haram. Indeed, pork is strictly Haram according to Islamic Law. So these products will become clear-cut Haram.
Further, ingredients derived from haram sources are Haram. In addition, utensils and equipment contaminated with haram substances will make the food Haram.
In Quran, Allah Ta'ala said,
"Prohibited for you are: carrion, blood, the flesh of swine, and those upon which
(a name) other than that of Allah has been invoked (at the time of slaughter),
animal killed by strangulation, or killed by a blow, or by a fall, or by goring,
or that which is eaten by a beast unless you have properly slaughtered it; and
that which has been slaughtered before the idols, and that you determine shares
through the arrows. (All of) this is sin."(Surah Al-Ma'idah – 3)
Further, a Hadith has it like this – On the authority of Abu Ya'la Shahddad ibn Aus,
the Messenger of Allah said:
"Verily Allah has prescribed proficiency in all things. Thus, if you kill,
kill well; and if you slaughter, slaughter well. Let each one of you sharpen
his blade and let him spare suffering to the animal he slaughters" (Sahih Muslim).
So in light of the above verse, the meat of the following animals is Haram.
Pork (pigs, boars, swine, hog)
Domestic donkeys, mules
Animals/birds (land and water) killed/ horned by predators
Animals/birds allocated to idols
Animals/birds died due to tormenting and other ill-treatment
Animals/birds stunned to kill
Animals with fangs/ claws or of prey (Lions, tigers, cheetahs, bears, wolves, cats, dogs)
Birds of prey (eagles, falcons, ospreys, kites, vultures)
Insects (excluding locusts)
Reptiles (lizards, snakes, crocodiles)
Animals that are commanded to kill (mice, scorpions, snakes)
Some other animals, like monkeys
Poisonous and hazardous aquatic animals
Animals/birds died from natural causes, falling from a height, and asphyxiation.
Even for Halal animals, there are some slaughtering rules to follow to avoid making the meat Haram. Therefore, the meat will either be Halal or Haram, depending on how the animals have been slaughtered in light of the Quran and Sunnah. Animals slaughtered/ dedicated to others than Allah or slaughtered without the name of Allah make the meat Haram.
Muslim dietary patterns can vary depending on the regions and Fiqh they follow. However, Islamic dietary strictures proposed by Quran and Sunnah equally apply to all Muslims.
According to Muslim dietary restrictions, it is completely Haram to include blood as part of one's diet. Also, all other Haram food (mentioned in detail above), pork, alcohol and derived beverages, and all intoxicants and poisons are haram and should not be a part of the diet.
If the food additives, cosmetics, and pharmaceuticals use the Haram animals' skin, bones, and hair, they will also be Haram to consume.
Alcohol, itself, has prohibition, so it cannot be a medicine drug or part of medications or allowable to use on the body. So groceries, additives, cosmetics, pharmaceutics, and other conveniences (products) with non-Halal products are Haram. Therefore, some Muslim denominations even count alcohol-based perfumes as Haram or doubtful to use.
Carrion refers to an animal that dies of illness or natural causes. According to Zabiha rules, animals must be alive, healthy, and conscious at slaughter time. Therefore, Carrion is considered to be Haram.
According to Islamic discipline, avoiding haram food and consuming only Halal food is obligatory. So as long as the food/ ingredient is Halal, it does not restrict the buying and eating of food items prepared and/or sold by non-Muslims.
Whey powder can be Halal if the Whey is from a Halal source like bacteria, synthetic processes, etc. Otherwise, Whey made of non-microbial enzymes and other non-Halal ways is Haram.