Catobophobia doesn’t exist, medically speaking anyway. But you’ve probably run in to someone who displays the symptoms.
The word is used to describe being constantly afraid that you are catabolic, or to put it another way – losing muscle.
If you are aware of your physiology then you will probably have heard of the anabolic window, this is the period after a workout where it is advisable to take on some additional protein.
The reason for this is that your muscles require it to recover from the session, whenever you lift weights you cause muscle breakdown. This is where the muscle fibres tear.
In an ideal situation the muscle fibres tear and then the protein that you ingest is used to stimulate muscle protein synthesis, which repairs the fibres, and rebuilds them to be stronger.
Theoretically a lack of post-workout protein could lead to a negative protein balance where the muscles are not supplied with enough protein to be repaired. In this scenario the muscle tissue would catabolise (break down). If you are trying to build muscle (or even to just preserve it) then this is a nightmare situation.
How likely is catabolism after a workout?
The thing is that if exercise occurred in a vacuum then immediate post-workout nutrition would be needed to prevent muscle loss, but it doesn’t.
Most people will have eaten at least one meal before reaching the gym (and if they haven’t then they really should), and a bodybuilder will probably have had at least 2 or 3.
Protein taken before a workout will still be in your system for a few hours, meaning that the anabolic window is much bigger than most people believe.
The only time when muscle loss is at all possible is when people are exercising whilst trying to lose weight (and they are in a caloric deficit). But if protein is kept high  then there really is nothing to worry about.
So what does catobophobia look like? Well it’s basically being worried that you’re losing muscle and therefore constantly trying to eat protein to prevent this.
One of the main symptoms is an inability to listen to reason, try telling a sufferer that they are in a calorie surplus and as such muscle breakdown is essentially impossible and they will ignore you.
Catobophobia is fun to laugh about but it really can affect people, some sufferers will wake themselves up during the night just so that they can get an extra meal in. This will really affect their sleep quality which ironically can blunt protein synthesis!
What it is really about?
Catobophobia isn’t an illness nor is it a disorder, it is a symptom of body dysmorphia. The same mental issue that leads to steroid abuse in men, and anorexia/eating disorders in women.
Having a poor and unrealistic self-image can make men feel like they are smaller than they are, or that they are losing muscle. Even when they are actually gaining muscle.
Catobophobia is irrational, and is basically a form of anxiety. But because bodybuilders are seen as vain or narcissistic the body dysmorphia is not treated with the same levels of empathy as other disorders.
Do you suffer from this?
Ask yourself this “Are you happy with your body right now, and if not does it cause you stress?” If so then you could definitely be suffering from some form of body dysmorphia.
Many people picture people with body dysmorphia as huge bodybuilders crying in a mirror because their left pectoral seems smaller. This is definitely the case, but it can also affect people with average bodies, or with overweight or obese bodies.
What you need to understand is that being honest with yourself and having a frank review of your body is fine. If you are overweight and want to do something about it then fine. If you are heavily muscle-bound but still want more, then this can be fine too.
There’s nothing wrong with trying to improve your current physique, chasing perfection is the whole reason bodybuilding exists. But if how you look is affecting your mood, or altering your sleep, or leading to general stress then this is not okay.
In this scenario there’s not much advice that an article can give, intellectually you probably already know that how you see yourself is not representative of how you actually look. But emotionally? Different story.
In this case you need to talk to someone about this, body dysmorphia might seem minor and catabophobia in particular but it can lead to more serious issues. Talking to your doctor is the best step.
 Pasiakos, S., Cao, J., Margolis, L., Sauter, E., Whigham, L., McClung, J., Rood, J., Carbone, J., Combs Jr., G., Young, A. 2013. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: A randomised controlled trial. The FASEB Journal 27(9): 3837-3847