Some trainees are complaining they are suffering knee pain when they are squatting.
First of all, I may ask the trainees that did they have any injury in the past or what was their sports background. Some trainees had knee problems before serious training, because they never train their legs properly. According to my coaching experience, I've found that a lot of people cannot do squat with full range of motion due to the mobility issue.
If you never perform proper form of squat, please don't jump to barbell squat on day 1 of training. It will destroy you and you will be afraid of performing any heavy lifting. Please follow a qualified coach to assess your mobility and ability first. I recommend a new trainee to perform split squat and step-ups instead of barbell squat, even dumbbell goblet squat is benefit to a new trainee, the trainee can learn how to perform squat with proper posture wit right tempo.
If the trainee is still complaining the knee pain, stop doing any exercises involving squat, uni-lateral exercises and step-ups. By the way, Squat is not necessary for fat loss anyway.
Can you lose fat without squat? sure.
If you can't do that movement, please don't force yourself to do it. It will be worse.
You properly can do Bi-lateral exercises like leg press, leg extension exercises, but I would like to encourage trainees to perform posterior chain exercises instead. Because most of trainees are quads dominant, and their posterior chains are super weak. For example, romanian deadlift, deadlift, glute ham raises, back extension, leg curl, good morning.
According to my personal experience, I normally do the following exercises to reduce my knee pain. Basically, if I stretch my quads (lengthen my hip flexors) and use foam roller to release tightness on my quads and ITband, the pain will be gone.
#Foam rolling your hip flexors and quads
#Foam rolling your IT band