This page will tell you everything you need to know about the dietary requirements for a hedgehog.
Staple Diet: My herd gets fed a custom mix of crushed high quality cat foods and Hedgehog Precision. I strongly recommend to avoid most foods labeled as "hedgehog" foods as they are full of filler and do not contain the correct nutritional content. Stick with cat kibble, it does not matter the brand, just aim for 30-35% protein and 10-15% fat. More protein or fat (no matter the source) than recommended can cause organ damage and diabetes. Watch out for fillers like soy, corn, wheat, peas, beats, grasses, meat byproducts, other fruit or veg, and the like. There is no kibble out there that does not include fillers, you just want them to be lower on the ingredients list, about 5-7 ingredients down. A mix of kibbles is ideal for variety. Hedgehog Precision is the only "hedgehog" labeled food that I have found to meet the correct nutritional requirements. They make excellent quality, correctly sized kibble, with appropriate density. Currently they offer their Standard formula, Weight Control formula, and High Calorie formula. Hedgehogs can become obese easily if overfed, which can lead to a number of health problems and even an early death. Hedgehogs only require roughly 1 to 2 tablespoon of food per day, plus live insects. A small food bowl will suffice for your pet’s needs.
Food Transitions: Always transition to new foods slowly. Mix in your new kibble of choice with the old kibble at 75% old, 25% new for a few days, then do 50/50, then 25/75, then you can move to 100% new. The entire process should take 1 to 2 weeks. You can also add a probiotic to help maintain proper GI balance and prevent upset stomach, gas, and diarrhea.
Insects: You cannot rely on your staple diet to give your hedgie it's total nutritional needs. Feeding them cat kibble is better than hedgehog marketed food, but it's still formulated for cats. Hedgehogs need chitin which is their fiber and that is found in insect exoskeletons. Hedgehogs eat bugs, period. If you can't or don't want to feed your hedgehog insects, then it is clearly not the right pet for you. Live insects are of course best, but they also come canned and dehydrated. Contrary to popular belief, canned and dehydrated insects do not loose all of their nutritional content during processing, but it is diminished. Dehydrated also comes with extra cons like constipation, impaction, and dehydration of your hedgehog. You also need to understand the nutritional content of each insect you plan to feed. They all have their pros and cons, but most importantly watch out for the calcium to phosphorous ratio (Ca:P). Hedgehogs need a ratio of 2:1 minimum, most insects are the opposite, where the phosphorous far outweighs the calcium. This is why it is important to "gut load" your insects with calcium rich foods, dust them in calcium powder, or dust your hedgie's food in calcium powder. Cat kibble will contain calcium and black soldier fly larvae contains more than 2:1, so both of those will help offset the other insects' terrible ratios, but not 100%. You can read about why Ca:P is so important here. It is also better to feed your hedgehog a few insects (10-20) everyday vs a large load once or twice a week. If you would like to learn how to farm your own insect colonies, a complete guide can be found here. If you need starter colonies or have no interest in farming but would like to provide your hedgie with a variety of high quality affordable insects, you can get a 10% off discount on your entire order from Dubiaroaches.com here (*full disclosure, I get a referral bonus in the form of points to use as dollars off my future orders). Below is a chart that lists each readily available insect's nutritional content.
Wild Caught: Do not feed your hedgie wild caught insects. Most insects from outdoors come with the risk of parasites of which they are only intermediary hosts for, meaning the goal of the parasite is to end up in a larger creature that will eat the bug. Some insects may have also been exposed to pesticides, you never know. During outdoor play, it is not the end of the world for your hedgie to scarf up a bug or two so don't fret, just don't actively seek out bugs from your yard for them to eat.
Supplements: If you can't, don't, or won't feed your hedgie insects, at the very least you should supplement with cricket (aka chitin) powder. You should be supplementing your live feeders with calcium rich foods or calcium powder (the kind used for reptiles, any brand). Exotic Nutrition makes a multi vitamin powder for hedgehogs called Hedgehog Booster, however I don't follow the recommended dose and only use it once a week. Hedgehog Precision also makes an Appetite Support powder which is meant to encourage your hedgie to eat its food and should not be used long term. You may find that you only need some of these supplements or none of them at all, each diet plan and hedgehog's metabolism will be different.
Variety: Just as variety is important for a human's diet, so too is it important for your hedgie's diet. You can add variety by once a week giving your hedgie plain scrambled eggs, pinky mice, day old chicks, plain cooked chicken breast, plain cooked fish, wet cat food, even jars of plain meat baby food, etc.
Fruits and Vegetables: Hedgehogs do not have a cecum, which is a section of the intestines (between the small and large). This is where enzymes that break up plant fiber are produced. From absolutely every study I have read thus far, vegetation has been found in the stomachs and feces of wild hedgehogs, but mostly whole (undigested) and the majority of it grass. Vegetation can be used to add bulk to stool if needed but nutrients are not utilized from it. That being said, it is not that they can never eat fruit or veg, but too much can cause problems like constipation and impaction. Please reserve any fruits and veggies for occasional treats only (once a week or less) and not part of their everyday diet. If you are feeding insects or supplementing chitin powder, they get will be getting all the fiber they need. Never feed any hard or dehydrated fruits or veggies, always cook or rehydrate or you risk pieces getting stuck in your hedgehog's hard pallet and choking.
Foods to Avoid: There are foods that your hedgehog absolutely cannot have. Below is a list of foods you should not feed your hedgehog.
Water: There is much debate over bottles vs bowls, here at Pixie Pets I use custom made water bottles with chicken nipples. Using spring loaded water bottles could cause chipped teeth and tongue injuries, while not extremely common, it does happen often enough that it is an unnecessary risk. Water bowls are perfectly acceptable, with the water being changed every day.
Bowls: Get a bowl that is heavy enough that your hedgie cannot tip it over (they are stronger than you think). Set it in the corner or next to a cage wall. Make sure you put it away from any soft fabric hides or fleece items, water will get wicked up in the fabric quickly and you don't want your hedgie sitting in cold wet all night.
Bottles: If your hedgehog is constantly biting their water bottle, it is usually a sign that the flow of water is not fast enough and you risk dehydration and tooth damage, it would be wise to switch to a different bottle or a bowl.