Vegan

Die-hard carnivores love their meat and don't want to hear anything against it.

Vegan diet is most in line with minimalism.

Minimal eating
Veganism, simply defined, is abstaining from animal products, from meat and fish and poultry to dairy and eggs and other such products. Going for whole foods that are minimally processed, means mostly eating veggies, fruits, nuts, seeds, beans and some whole grains.

This limited, minimal diet, can be incredibly satisfying and maximally flavorful. It's also very healthy and light.

Easy to prepare, with a minimum of fuss.

The most sustainable diet
Figures are well covered elsewhere. Raising animals for meat, eggs and dairy is incredibly wasteful. For every pound of meat or dairy, many times that amount of plants must be used to feed the animals for those products.

Animals also produce a huge amount of pollution and contribute immensely to greenhouse gases, not to mention the machinery and fuel that's used to raise, slaughter and transport them, and all the plants needed to feed them. They contribute hugely to deforestation and other environmental problems as well.

Eating only plants cuts that waste to a minimal amount, and is so much better for the environment. Minimalists who care about living lightly and sustainably would do well to research this and consider it.

Minimal cruelty
One of the main reasons for becoming a vegan is that animals shouldn't be held captive, suffer, and be slaughtered for human pleasure.

There is absolutely no need for humans to consume animal products to live a healthy life. Sure, humans have eaten them for millions of years, but as millions and millions of people have proven, a vegan diet is healthy.

The only reason to eat animal products is pleasure, not being able to give up the taste. Becoming vegan means opting out of a society that treats animals with extreme cruelty and pretends it doesn't happen.

This applies to factory farming, but also to free-range, grass-fed animals. Some vegans don't believe animals are objects that should be used for our pleasure, kept captive and killed, no matter how "humanely" they're treated while alive. This is akin to slavery of a fellow thinking, feeling creature. Animals don't exist for human benefit. They exist for their own benefit.

Another justification commonly made is that vegetarians kill plants, and those are living things too. However, they don't feel and think and suffer in the same way that humans and animals do. They don't have a central nervous system or brain. It's a fallacious argument. Carnivores have no problem with killing plants, and are only pointing this out to make vegans look inconsistent.

Living lightly, not always conveniently
Veganism can sometimes be inconvenient, when eating at restaurants that aren't vegan-friendly or at the homes of non-vegan friends or family.

That's a reality, but for most days, it's not that hard to avoid problems whatsoever.

More and more restaurants are becoming vegan-friendly, and the ones that aren't can usually whip up a quick and simple vegetable dish on request. Avoiding most fast food is a good idea anyway. At someone else's house, bringing a dish is a solution to not being offered a vegan dish out of consideration.

Starting small could mean trying a couple vegan dishes progressively.