Some people believe you need to use lower weights and do higher rep training when you are trying to drop body fat. I've also heard you will lose a lot of strength whilst dieting. For the purpose of this article I am referring to anything over 10 reps as being higher reps.
As a powerlifter it's very important to me that I keep my strength while dieting. By keeping myself in a calorie deficit through diet and increased activity levels I am able to drop body fat and maintain my strength. Maintaining my strength is done by lifting heavier weights for less reps as opposed to increasing my reps.
It’s important to make sure you train your muscles hard while dieting to force the body to retain as much muscle as possible. Whilst dieting your main concern should be to retain muscle and drop fat, training hard will improve your chances of minimising muscle loss. I’m certainly not saying you can't train hard with lighter weights, I just prefer to use heavier loads to maintain my strength and let the diet and cardio do the rest.
Also I'm not saying higher rep training will not work to help you drop body fat because it will if you are in a calorie deficit. However, because a lot of people go down this route they will end up losing strength but they don't understand the relationship between their training and results. It's not the diet making them weaker it's their training. Your training should always be specific to your goals. You wouldn’t train for a 10k race if you wanted to get better at sprinting would you?
If you try and drop fat slowly, decreasing your calorie deficit over a matter of weeks and months you should be able to maintain the majority of your hard earned strength.