This isn't just a survival game where you take care of your vitals. Cannibals will constantly attack every couple of nights, increasing in size and damage. You'll want to make sure your base has a good system for collecting food and water when times get tough.
More enemies can come as you're recovering from the last wave, so it's crucial to stock up on all you can! There are different tricks to staying alive and healthy in The Forest. If you have this down, you can put your focus into other things like better weapons and armor.
Have Your Base Near A Pond
Ponds are valuable. They have fish, water, and sometimes swimming water. Water deep enough to swim in allows you to wash off blood so you don't get infected. The pond water can be scooped up with a crafted waterskin pouch or an old pot. The fish can be constantly hunted with a bow for deep water or your axe for shallow water.
This also helps for a quick rinse if you accidentally light yourself on fire more than once. You can carry three fish at a time. Kill all the fish in the pond and hang them up on a drying rack for when you need them. It takes a while for more fish to respawn, but they will eventually so you don't have to worry about killing a population. If it hasn't rained in a while you can run to the pond with your pot and stand at the very edge to collect some polluted water. Cooking this over the fire is quick enough and fills your thirst levels completely.
Rabbit Traps
Make a lot of traps for food. They don't just collect rabbits, but any four legged animal running about. Lizards can get trapped in these too, so you can collect both food and armor from the lizard skin.
You can't really take the animal out and then kill it as it will sprint away as soon as you free it. The best option is to kill it while it's in the trap. This can be hard because you might destroy the trap itself and have to build a new one.
If it's a lizard, half of its body will be outside of the cage anyway so you can use your axe to bonk it right in the head without damaging the trap. If it's a rabbit inside, you're best off just using a bow. Kill the rabbit with a bow as it's inside and you should be able to skin it and collect the meat without opening the cage. Realistically this shouldn't be possible, but it is and it sure is helpful. It's best to put multiple traps around the perimeter of your base.
Fire Pits And Drying Racks
Multiple fire pits will do you justice. You can cook multiple slices of meat on one, but it gets complicated if you're boiling polluted water or sharing things with other players.
With more than one fire pit, you can have a designated pit specifically for water or soups using the old pot. If you can't find turtles to make a water collector or you need more stocked up water, you can have pots at the ready on fire pits.
Drying racks are crucial because if you don't have a place to store all types of meat, it will be gone with the wind if left on the ground. You will need dozens and dozens of drying racks. A couple for real food to hang and a couple for the body parts of cannibals. Food that has been hanging for a long time cook way faster so you don't have to wait at the fire in dire times.
Restock Duty
All this takes a lot of in-game days and effort if you're doing it alone. You also have to worry about fending off cannibals and demons as well as building a base that actually protects you. A friend or two goes a long way.
If you would rather collect valuable resources on expeditions like medicine and cloth and someone else is building the base, it's time to put someone on restock duty. The fish won't hang itself. If someone is on top of collecting fish, checking the rabbit traps, and filling pots with water, the team will never be hungry.
Water
Last but not least, water. You can find an old pot in multiple parts of the map near sleeping bags and this will help you collect water, but there are other ways. You can craft a water collector so that whenever it rains, the tub fills up. You can just sip out of this since it came straight from the clouds unpolluted.
To craft this you need a turtle shell and sticks. Sticks are easy enough, but you have to travel to a beach to find turtles. Smack their head a few times, then skin them. Once you skin them, all that's left is the shell which you can pick up. The shell can also be used as a sled. Apart from a water collector and pot, you can craft a water skin pouch. This will allow you to bring water on your journey if you plan to go far and into danger. You have to collect water from the water collector or boiled pot with it for purified water. Any other source will be polluted and would therefore only be useful as a last resort. It's crafted by combining two deer skins and one rope.