Introduction
Well...I think the title of this thread is pretty self-explanatory, to be honest! Basically, I had noticed that there are a lot of myths and misunderstandings about hamster diets floating around. I wanted to make a concise list of these myths and the explanations as to why they're wrong.
I would like to thank HoppingHammy and tbiM20 for their help, guidance, and editing on this project. I would also like to thank all of the knowledgeable members (special shout-out to nebit!) who help us all to learn and grow.
If anyone has any questions, critiques, or suggested additions, please feel free to mention them!
Myths List
MYTH - Seeds are inherently fattening and unhealthy, and should only be fed as rare treats.
FACT - Seeds are a vital part of a hamster's diet, and have various nutritional profiles, pros, and cons.
This myth comes from the fact that seeds are indeed not the best food for some small animals, including guinea pigs, rabbits, and chinchillas. However, it's important to remember that these are different animals with different dietary needs. Rabbits, chinchillas, and guinea pigs are grazers, and they feed primarily on grasses, plant stalks, and leaves. Seeds are not a major part of their natural diet, which is why they are not recommended for captive animals.
However, hamsters are not grazers - they are foraging omnivores. In fact, they are most accurately described as granivores ("seed eaters")! Seeds are not only acceptable, but an important part of their diet. Saying that hamsters shouldn't have seeds is like saying that dogs shouldn't have meat, or that cows shouldn't have grass.
Not all seeds are high in fat. In fact, most grains (wheat, rye, barley, spelt, quinoa, etc.) contain very little if any fat, and are loaded with nutrients, fiber, and complex carbohydrates.
Part of the reason seeds get a bad reputation is because many store-bought hamster seed mixes are known for being low-quality and unhealthy. But these foods are not unhealthy because seeds are inherently bad. Usually, the biggest issue is that they're not balanced. Many seed mixes contain large amounts of corn (which is a low-nutrition filler). Seed mixes also might contain the wrong combinations of seeds (too many high-fat seeds, not enough grains). Finally, seed mixes can be poor-quality due to factors that have nothing to do with seeds - added sugars, artificial dyes, dangerous preservatives, etc.
It's important that we don't blame seeds themselves for the shortcomings of many seed mixes. Seeds, in the correct quantities and proportions, are a vital part of a hamster's diet.
MYTH - Hamsters should have a diet of straight pellets / block food. Feeding a seed mix is bad because given the choice, hamsters will only eat the tasty junk food in the mix and not get balanced nutrition.
FACT - Hamsters are foragers that do best on a high-variety diet that includes pellets, seeds, nuts, plant matter, and animal protein. There are ways to feed a balanced diet with a seed mix.
As discussed above, seeds are an incredibly important part of a hamster's diet. All hamsters should have a seed mix in their diet.
If a seed mix has "junk food" in it, it's not a good seed mix and shouldn't be fed in the first place. There are a huge variety of seed mixes available - some are excellent, some are terrible, and plenty are in between. Choosing a proper, healthy seed mix is the first step to feeding a good, high-variety diet.
Then we come to the issue of the hamster picking out only certain parts of a mix and leaving the rest. This is called "selective feeding" and yes, it can be an issue with some hamsters. Selective feeding is a big argument for feeding a pellet-only diet. Obviously, feeding only pellets will prevent selective feeding. However, that's kind of like saying that a person with allergies should be locked in a hospital their entire life and never allowed outside. It works, but the solution is extreme and is worse than the original problem.
There are much less extreme solutions to ensure a balanced diet than removing all variety. One common solution is simply to not refill the food bowl until everything is consumed, to ensure the hamster eats all parts of the mix. Another option is to switch to a more palatable mix - hamsters have taste preferences just like humans do!
MYTH – Hamster mixes contain "filler pellets" that contain no nutrition and can be picked out of the mix with no issues.
FACT – The pellets in mixes are the source of vitamins and minerals!
This is a relatively recent myth, but it is an extremely dangerous one.
First of all, never remove anything from a packaged hamster mix. All hamster mixes need to be fed as-is, because their nutritional levels are calculated using all ingredients in the bag. Once you start removing things, you change the ingredient ratios and therefore the nutrition of the food. This is true even if what you're removing is just filler. For example, if you remove fat-free filler from the mix, you're increasing the proportion of higher-fat ingredients, and therefore raising the fat content of the mix.
1) The entire purpose of pellets it to deliver the added vitamins and minerals in the food. This is just how human-made pet food works. Ingredients are ground up and extruded into a pellet. The vitamins and minerals that need to be added to the food are either mixed into the ground-up ingredients or sprayed on the outside of the finished pellets. This is true of nearly all pet food. Bear in mind that dog and cat kibble are nothing but pellets! Are they all filler as well?
2) The "waste ingredients" that filler pellets are made of have nutrition after all! Filler pellets are often said to contain garbage ingredients like seed hulls and alfalfa hay. It turns out, these ingredients actually are nutritionally beneficial. Alfalfa is an extremely nutritious type of hay - it is specifically recommended for young rabbits and guinea pigs because of it's high nutrient content. It's relatively high in protein, extremely high in fiber, and contains nutrients like calcium, phosphorous, and magnesium. Seed hulls may not sound all that great, but the truth is that they have a ton of fiber. So these supposed filler pellets likely provide most of the fiber in the seed mix.
3) The method used to decide which pellets are filler and which ones are not is completely arbitrary and nonsensical. Most hamster mixes have different types of pellets. This entire myth hinges on the idea that some pellets are filler, but others are not. The problem is that which pellets are filler seems to be based on completely irrelevant factors such as size, shape, and color.
The bottom line? Filler pellets do not exist.
MYTH - Corn and peas are non-nutritious sugary junk food and need to be removed from commercial mixes.
FACT - These ingredients should not be removed for various reasons.
First, we again come to the fact that commercial mixes are designed to be fed as a whole. Removing ingredients alters the overall nutrition of the mix. Peas are actually a great example of this. Peas are a whopping 25% protein, which is quite high. They are a major source of protein in many mixes. Removing peas will lower the protein content of a mix substantially! If you have a mix that's 18% protein and you start removing peas from it, it's going to end up with less than 18% protein.
Corn also serves an important purpose. It's in the mix to keep it balanced. Removing the corn results in a mix that is too rich, because it increases the proportions of the other high-fat and high-protein ingredients. Nebit has a really excellent post explaining this right here.
Second, the corn and peas found in hamster mixes contain virtually no sugar at all.
The dried corn in hamster food is not the same as the sweetcorn that we eat. This should be obvious just from touching it--the corn we it is soft and squishy. The corn in hamster food is rock-hard. The corn in hamster mixes is known as field corn, feed corn, or dent corn. The biggest difference is that field corn contains very little sugar compared to sweetcorn.
Peas are a similar situation. The peas in hamster food are not the sweet peas or snow peas that many people are familiar with. They are actually split peas or green peas. These are an entirely different variety, and have very little sugar in them.
MYTH - High-fat foods (pumpkin seeds, sunflower seeds, egg yolk) are inherently "bad" or "unhealthy" and should not be fed if possible. Lower-fat alternatives (such as egg whites) are always a better choice.
FACT - Fat is not a bad thing, and fat content is not the sole factor in deciding if something is healthy or not.
Despite its bad reputation, fat is not evil or bad. All animals need fat to survive--it is crucial for energy, growth, and development. Fats and oils are essential to skin health and coat health. Excess fat is bad, of course, but that could be said of literally anything. With all things, moderation is key.
It doesn't make sense to judge a food as "healthy" or "unhealthy" only by its fat content. Just because something is high in fat does not mean that it is unhealthy, and just because something is low in fat does not mean that it is healthy. It's important to consider the overall nutrition that the item provides.
For example, jelly beans, gummy bears, and soda are all fat-free foods. Are these things usually considered healthy? No! Because despite being fat-free, they are loaded with sugar and provide no useful nutrition. On the other hand, think of things like nuts, beef, and milk. These things all have fat in them, and some are actually high in fat. But they are universally healthier than the items listed above, because they provide actual nutrition in the form of proteins, vitamins, and minerals.
As for low-fat alternatives being a healthier choice, this isn't always true. Egg yolk much higher in fat than the white. However, the yolk is also where most of the nutrients in the egg are - it contains more protein, vitamins, and minerals than the white! While the white has benefits as well, it isn't automatically better than the yolk because it's lower in fat.
MYTH – Millet is like candy for hamsters, and should be fed rarely or not at all.
FACT – Millet is a perfectly healthy seed that can be fed even daily, in reasonable quantities.
Millet gets a terrible reputation, and there really isn't any reason for it. There’s nothing about it that could even be misinterpreted as being unhealthy. Millet is a good source of fiber, and has good complex carbs that help to mitigate blood sugar spikes. Granted, it’s not absolutely packed with vitamins and minerals, but it is a good source of manganese, and has other nutrients as well.
MYTH - Diabetes-prone species (Campbell's, Winter Whites, and Chinese) should never have sugary foods like fruits, as it will increase their risk of developing diabetes.
FACT - Nutritious sugary foods are perfectly fine to feed in limited, reasonable quantities
Let's start with the risk factors of diabetes. Diabetes is largely genetic (both Type 1 and Type 2). Yes, there are absolutely lifestyle factors that contribute to it, but there is a genetic component as well. So while a healthy diet is important for all hamsters, diet is not the be-all, end-all of diabetes.
Now, let's move on to sugar. First off, we need to dispel one of the biggest myths in hamster care.
Sugar does NOT cause diabetes.
Sugar is not some magic switch that causes diabetes to just poof out of nowhere. I often see people panicking because they fed their dwarf hamster a piece of fruit and are afraid it will get diabetes. This simply will not happen.
This myth exists because in humans, certain types of diabetes are sometimes correlated with a diet high in processed, refined sugars. In other words, junk food like soda and candy. But that's not because sugar itself causes the disease. No, it's actually much simpler than that. It's because eating lots of junk food can make you fat. And being obese can lead to insulin resistance, which may in turn lead to diabetes. It's not the sugar itself that's the problem--it's the issue of over-consuming and gaining weight because of it. And even obesity does not automatically mean that a hamster (or human!) will become diabetic. It increases the risk, sure, but it's not a guaranteed thing.
That brings me to my second point. Because the issue is obesity and not sugar, literally anything that can cause weight gain can technically increase the risk of diabetes if overconsumed. It's not just excess sugar that can be a problem, excess fat is bad as well. But please note the word "excess." Fat and [natural] sugar are not bad for hamsters - it just needs to be fed in reasonable, moderate quantities.
This brings us again to the topic of moderation. There's no reason that dwarf hamsters can't have a piece of fruit or even a sweet treat every so often...as long as it's not being fed to the point that it causes weight gain.
MYTH - Fresh meats, tofu, and eggs are great ways to boost a low-protein staple diet up to suitable levels.
FACT - Most "wet" protein sources do not provide enough protein to boost a low-protein staple diet.
Foods like beef, chicken, turkey, eggs, and tofu are known as being "good sources of protein," which has led many hamster owners to assume that they are a reliable way to boost a low-protein diet up to suitable levels. Surprisingly, this simply isn't the case!
These foods are considered high-protein because most of their calories come from protein. However, this does not take into account their moisture levels, because water does not provide calories.
Because of their water content, many of these foods provide less protein than we would think!
For example, 100 grams of egg provides 13.0 grams of protein. But 100 grams of, say, Oxbow (15% protein, which is considered low for hamsters) provides 15.0 grams of protein. So egg provides less protein per 100 grams than even a low-protein hamster food. The same is true for tofu, which is similar in protein content to eggs.
Most meats (chicken, turkey, beef) provide about 30.0 grams of protein per 100 grams (so 0.3 grams per 1 gram) This is higher than pretty much any hamster food, that's true. However, would this addition be enough to boost protein to acceptable levels? Let's do the math and see:
MYTH - There is a single "best" commercial hamster food that represents a perfect diet.
FACT - Every commercial food has different pros and cons--none are perfect, and the best results come from mixing several ones.
We often have new members coming on the forum and asking what the "best" hamster food available is. The thing is, there really isn't one commercial food that hits all of the important points perfectly. There are certainly good choices, but having an excellent diet requires a bit more work, and generally involves mixing foods.
There are 3 main factors to look at when it comes to hamster diets
Nutrition - Proper levels of protein, fat, fiber, vitamins, etc.
Variety - A good mix of different ingredients, flavors, and textures
Ingredient Quality - Balance of nutritious ingredients versus low-nutrient fillers and junk food
There really isn't any one food that does all 3 of these things super-well. Many foods that have great variety are sometimes lacking in nutrition or use lower-quality ingredients. And foods that have good nutrition sometimes lack variety (this is true of many lab blocks).
The other issue here is that not all hamsters need the same nutrition! Age, physical condition, general health, and things like that all vary from hamster to hamster. What works for one animal may not work for another.
MYTH - Oats should be strictly limited because excess fiber can cause constipation.
FACT - Reasonable quantities (a small pinch per day) of oats will not cause constipation, as oats do not contain nearly enough fiber to be considered "excessive."
The reason this myth exists comes from human health issues being applied to hamsters.
Fiber is an excellent constipation remedy for human beings, largely because we cannot digest it. The fiber passes through our systems undigested, and serves to bulk up stools (to stimulate bowel movement) and to retain water. Both of these factors help to prevent constipation. However, it's also possible for fiber to have the opposite effect. If humans eat too much fiber and don't drink enough water, the result is bulked-up, dry stool...which definitely leads to constipation.
However...hamsters have a different digestive system than we do. They have a section of intestine called the cecum, which is home to various bacteria that are able to break down fiber. Hamsters can do something that we cannot--they can break down fiber via the bacteria in the cecum.
Now, fiber is still important to hamsters in the sense that it feeds and keeps those bacteria healthy. However, things do work a bit differently for them regarding fiber. And since hamsters can indeed digest fiber, there's no reason to believe it would cause the same types of blockages. This isn’t to say that excess fiber cannot cause other problems (too much of anything can be bad!), but the idea that it works exactly the same as in humans doesn’t make sense.
Furthermore, oats do not really contain that much fiber. They are only about 11% fiber, which is in line with what hamsters need on a daily basis anyway. So even a diet of 100% oats would not provide "too much" fiber (though it would cause many other problems, such as malnutrition, so obviously this is not advised!).
MYTH - Lentils are bad for hamsters, because they contain toxic chemicals.
FACT - Lentils are perfectly safe, because the "toxic" chemicals are unlikely to be harmful to hamsters
Let's start with the supposed "toxic" chemicals. The compounds in question are called lectins, which are specific types of proteins. Lectins act as plants' defenses against insect pests--they're a natural compound that discourages bugs from feeding on them. Some people believe that lectins can cause varying degrees of digestive troubles in certain sensitive human beings (this is very much debatable, however). And it is true that lentils are very high in lectins.
Here's the problem with lentils supposedly being toxic to hamsters. Nearly everything that we feed our hamsters is high in lectins. Because they are plant defenses, all seeds, nuts, and legumes are positively loaded with them. This includes the wheat that makes up our hamsters food pellets, the peas that give them protein, the sunflower seeds that give them healthy fats. It makes little sense to say that lentils are bad for hamsters, because in all likelihood, they're getting way more lectins in their daily diet than in a small pinch of lentils.
It may possibly be true that feeding extremely high-lectin foods like lentils and beans in very high quantities can cause health problems. However, yet again, we come to the idea of moderation. As long as the hamster isn't getting tons and tons of lentils, there's no reason to believe that they are harmful.
MYTH - An overweight hamster should be given less food to help it lose weight
FACT - Hamsters do not overeat, and should always be given free access to healthy food
Hamsters typically get fat because of what they eat, not how much they eat.
Hamsters do not generally overeat. They are able to store their food pretty much indefinitely, so they have no reason to gorge on food. A hamster will only eat as much as it needs to. If you have a hamster that eats 10g of food per day, it's only going to eat 10g / day, regardless of whether you give it 10g, 50g, or 100g of food.
As with most things, there are exceptions to every rule. Hamsters can sometimes overeat in extreme situations (like very high levels of stress, certain illnesses, etc.), but this is pretty rare.
If your hamster is overweight, it probably isn't because of overeating. It could be a health issue, lack of exercise, or the type of food that's being fed.
Edited by Taxonomist, 27 February 2019 - 01:33 AM.
Tax great job on this! 
