can snakes get fat?
Snake Health

Can Snakes Become Overweight?

Snakes can experience a variety of health problems, but can you have an overweight snake? Perhaps you’ve noticed that your snake doesn’t seem to know when it should stop eating and that it’s grown much larger than other snakes that you’ve owned or seen in the pet store.

Boas and pythons can get very fat since they are mostly sedentary. Corn snakes and similar, active snakes are less likely to become overweight. You can tell if a snake is overweight because of ‘scale spreading,’ where their skin shows through the gaps between the scales.

We’ve created reference tables that you can use to make sure that your snake is within a healthy weight range. Just because a snake is ‘overweight,’ it doesn’t mean they’re unhealthy, because some snakes are naturally much longer and bigger than others.

Do Snakes Have Body Fat?

Snakes do have body fat to store energy for later. They have very slow metabolisms, and will happily go for weeks or months without eating, and body fat can provide enough energy for them to last for a while. These fat reserves are subcutaneous, meaning ‘just under the skin,’ like humans.

Snakes also have ‘visceral fatbodies,’ which means areas where there is a larger-than-average amount of fat. Think of the area around your kidneys, where fat is stored on the human body.

However, there is one crucial difference between us and snakes when it comes to body fat. They don’t keep body fat to store heat, because they don’t produce body heat. They’re ectothermic, which means that they rely on external sources for heat. There’s, therefore, no internal warmth for the fat to absorb.

This has many positive and negative effects. While it means that they use up to 99% less energy than an endothermic animal (animals that produce their own body heat), it also means that they have to go into a period of low activity during the winter. However, snakes do have a thin layer of body fat to store energy.

Can Snakes Get Fat?

Captive snakes are prone to getting fat because they don’t burn off the energy they eat. If you overfeed them, their metabolisms are too slow to get rid of the excess energy.

This problem is exacerbated because a snake doesn’t know when it’s eating too much food, so it won’t refuse food because it’s overeating.

This applies especially to boas and pythons, which are sedentary snakes. Other snakes, like colubrids and elapids, are far more active and so stand less chance of getting fat.

how to tell if your snake is overweight

It also depends on the season. According to a paper written for the journal American Zoologist, snakes and other reptiles store more body fat just before the winter months.

This is perfectly natural, but this same biological instinct can also cause them to store far too much fat from their diet if you’re overfeeding them.

A snake cannot get fat on a normal diet, however. If a captive snake is fat, it’s because the owner has been ‘killing them with kindness’—feeding them too much food. When a snake gains weight, it will add fat stores both under the skin and in pockets around the body. This will make the snake look thick, especially around the middle at first, but then throughout the body.

Can Snakes Get Obese?

In everyday language, obesity refers to being exceptionally overweight. Of course, it’s possible for a snake to get exceptionally overweight, if the owner consistently feeds them too much.

However, it is also a medically defined term that refers to anybody with a BMI (body mass index) of more than 30. Being overweight is medically defined as a BMI between 25 and 29.9, for reference. Since snakes have a different body structure and don’t store fat in the same way as humans, you can’t say that a snake is medically obese in the same way that a person can be classified as obese.

However, it’s clear to see that snakes in captivity can become overweight, perhaps even obese. Again, this is because the snake’s owner has been overfeeding them. This can easily be done, because some owners don’t appreciate that a snake’s diet has to slow down a lot once they reach two years of age. At that age, you should start feeding them larger portions, but less often.

Snake Average Weight and Length

Snakes of all species generally follow a pattern as they grow. They will grow very quickly for the first year or two years of their life, before ‘plateauing’ and growing slowly from there on out.

Members of the same species will normally hatch and grow at roughly the same rate, although there are always outliers. The only other factor you have to consider is whether the snake is a male or a female, as the two sexes typically differ in size.

Let’s take a look at the hatch length and weight of the five most common pet snakes.

Average Weight and Length of Hatchlings

SpeciesHatch Length (Male)Hatch Length (Female)Hatch Weight (Male)Hatch Weight (Female)
Ball Python:10-16″10-16″65-100g65-100g
King Snake:8-11″8-11″9-14g9-14g
Corn Snake:10-15″10-15″6-8g6-8g
Boa Constrictor:14-22″14-22″50-60g50-60g
Milk Snake:5-10″5-10″4-8g4-8g

Hatchlings come out at the same length and weight, regardless of sex. It’s only once they start getting to sexual maturity—at between one and three/four years—that you start to see a difference in size between the sexes.

There is also a huge variance in the size and weight of hatchlings, even outside the ranges described above, so don’t think that your snake is ‘abnormal’ if they aren’t as described above.

For the first year of a snake’s life, they’re going to grow very quickly, so much so that you will notice the difference week by week if not day by day.

Average Weight and Length Snakes (1-Year-Old)

SpeciesYearling Length (Male)Yearling Length (Female)Yearling Weight (Male)Yearling Weight (Female)
Ball Python:30-40″30-50″500-800g500-1000g
King Snake:24-30″24-30″250-300g250-300g
Corn Snake:24-40″24-40″35-80g50-100g
Boa Constrictor:36-50″36-50″800g-1KG800g-1KG
Milk Snake:15-40″15-40″100-500g100-500g

At this point, females start to get longer and heavier than males. After two years, you should stop feeding for growth and start feeding them for sustenance.

That is, unless your snake is underweight and a problem feeder, in which case you should keep feeding them to try and get them to full adult size.

Average Weight and Length Snakes (2-3 Year Olds)

SpeciesAdult Length (Male)Adult Length (Female)Adult Weight (Male)Adult Weight (Female)
Ball Python:40-50”50-60”1300-1700g1400-1900g
King Snake:35-37”39-41”300-600g700-900g
Corn Snake:40-60”30-50”500-700g700-900g
Boa Constrictor:60-90”70-100”8-12kg10-15kg
Milk Snake:20-60”20-60”300-1300g300-1300g

Bear in mind that variance in the size and weight of a snake species is perfectly normal. Milk snakes are a perfect example. There are two dozen different milk snake subspecies, and some grow much bigger than others do.

Some snakes are bigger than others because of their genetics. If you know for a fact that you’re feeding your snake a normal diet, and you can’t spot any signs of your snake being overweight for their length, then it’s likely that there’s no problem.

How to Tell If Your Snake Is Overweight

Scale spreading is a term that refers to your snake’s scales moving further apart, so that you can see the skin below. This happens when the snake gets so large around the middle that the scales aren’t big enough to cover the surface area of the snake’s skin.

A small amount of scale spreading is perfectly normal after a snake has a large meal. However, if scale spreading occurs but doesn’t go away, this is a sure sign that the snake is overweight.

In the worst cases, you will also notice scale spreading elsewhere on their body, like behind their head. Scale spreading itself isn’t much of a problem, it’s a symptom.

Other Snake Obesity Symptoms

A snake that’s overweight will also display other symptoms.

  • The snake will be large around the middle. This is normal after a large meal, but if they’re overweight, they will have excess weight around their gut.
  • Snakes usually feel quite firm and muscular when you hold them. An overweight snake will quite literally feel heavier, but will also feel softer than a snake of average weight.
  • Inactivity is both a cause and a symptom of obesity/being overweight in snakes. This is especially the case during handling, when most snakes are quite active.

If you’re still not sure whether your snake is overweight or obese, take a look at some of our care guides. They can tell you how long and how heavy each snake is on average. We have guides on all of the most common pet snakes.

Snake Overeating Health Problems

If a snake eats too much, they can have similar health problems to an obese person. Their arteries can become clogged with fat, and they can have liver and kidney problems because of excess fat.

These issues shorten the life expectancy of a snake considerably, so it’s wise to do something about the problem before it gets out of hand.

do snakes have body fat?

Differences Between Snakes

Some snakes are naturally thinner than other snakes. A ball python is normally quite thick around the middle as it is. A corn snake, by contrast, is thinner. A green snake is thinner still.

That’s why it’s important to diagnose your overweight snake by looking at a variety of influencing factors, not just whether they look thick and chunky.

What to Do If Your Snake Is Obese

If your snake is obese, you should put them on a controlled diet. If you have a feeding schedule, adjust it so that you are feeding your snake less regularly.

To help your snake lose weight, you should consider either halving the amount that you feed your snake, or doubling the amount of time in between feeds.

Will Dieting Hurt My Snake?

Now, your first reaction is probably to think that this would be ‘starving’ your snake. After all, if we could only eat half portions of food each mealtime, we’d probably be pretty hungry. But snakes don’t experience hunger in the same way that humans do, since their metabolisms are different to ours. They don’t need to feel hunger like we do, because they don’t need to eat regularly.

Take brumation for example. Over the winter, many snakes brumate, especially those in cold climates. If you didn’t know, brumation is a period of low activity similar to hibernation. When a snake brumates—even for some time before they start brumating—they completely stop eating. It’s triggered by cold temperatures and lower light levels.

Brumation can last for three to four months. Snakes eat nothing during this period because if they did, they wouldn’t be able to digest, as they need to bask in warm sunlight to digest food. So, reducing your snake’s caloric intake by half is going to be perfectly fine.

What Else Can I Do?

Add something to your snake’s enclosure that they can climb. Branches work well, as do non-natural plastic items.

These encourage your snake to move around a little more which will help them burn extra fat. In the same way, handling your snake more often will get them ‘exercising’ too. Don’t handle them too much as this will make them stressed.