Hello Daniel and welcome to the forum.
To some degree, you’ve done well to drop down to 165lbs, but since you’d not been sensible with your method of weight reduction, such a severe calorie restriction will have no doubt led to a fair amount of muscle loss, as it will have been broken back down into amino acids and used as fuel to provide your body with energy it required.
Granted, some fat will have been lost in the process, but since it’s easier for the body to break down muscle mass when it’s placed into a severe deficit, that’ll be why a lot of body fat still remains.
If you research the term ‘catabolism’ all should hopefully become clearer.
Moving on, although you’ve increased calorie intake back towards a sensible level, have you consulted BMR and TDEE calculators?
Both will allow you to gain a clearer idea of how many daily calories you should be consuming in order provide your body with the nourishment it needs (BMR) and how many calories you should be consuming to meet your level of activity (TDEE).
Equally, I’d recommend consulting macro-nutrient calculators, in order to provide you with an idea of how many calories should be obtained between the respective food groups.
On the subject of macro-nutrients, given that you’ll have lost a fair amount of muscle mass, you should ensure that protein accounts for 35-40% of your daily intake, to help replace what will have been lost. As such, for the next 4-8weeks, I’d work to the following split:
40%protein/40%carbohydrate/20%fat.
Returning to BMR and TDEE, since you’ve presented your current statistics, I’ve calculated your BMR for you. As such, your BMR equates to 1368Kcal. In order to ascertain your TDEE (how many daily calories needed to maintain weight, based upon activity level), you should multiply 1386Kcal by one of the following:
Sedentary (little or no exercise): 1.2
Lightly Active (Light Exercise 1-3 days per week): 1.375
Moderately Active (Moderate Exercise 3-5 days p/w): 1.55
Very Active (Heavy Exercise 6-7 days p/w): 1.725
Extremely Active (Very heavy exercise/training 2 times per day): 1.9
Since you’ve not stated your current level of activity, it’d be impossible to say by which number you should multiply your BMR. However, most people’s level of activity places them into the first three categories.
As for burning fat through exercise, the quickest and most convenient way is to introduce HIIT cardio into your workout schedule. However, without knowing your current level of fitness, I would advise against its immediate introduction, choosing to increase the intensity of your cardiovascular exercise gradually over a number of weeks, instead.
Additionally, and somewhat most importantly, your chosen method of weight loss won’t have just affected the strength and endurance of skeletal muscle, there’s a fair chance that it’ll have affected the strength and endurance of your heart.
Don’t forget, your heart is simply a muscle and the catabolic effect of severe calorie restriction will have no doubt impacted upon it, hence the reason I’d mentioned a gradual increase in the intensity of your cardio exercise.
As for resistance training, seek to incorporate compound movements, such as the squat, lat pull down, chest press and shoulder press. In terms of the weight used, crucial for increasing size and mass, choose one that allows you to reach failure between 8-12 reps. Additionally, aim for 3-4 sets of 8-12 reps per muscle group.
Concentrate upon performing compound movements first before working muscle groups in isolation, whilst ensuring that you place emphasis upon the lowering phase of each movement (taking 2-3 seconds to lower the weight back to its starting position), since the eccentric phase is where muscle building takes place.
