I started at a weight of 235 on 9/1 and my goal is to loose about 1.5 lbs a week. For 3 weeks I have pretty well mantained this 1.5 loss per week; however this week, after working out hard and maintaining a diet of 1800 calories a day, I have gained 1.8 lbs. I will say that my bodyfat has come down 1% and I have lost 1/2 inch in my waist this week. I would think with my calories being so low that muscle gain would not be a factor. Is it normal to gain weight like this while working out?

Thanks,
Bob

Given your current bodyweight, it's hard to imagine a weight gain on 1800 cals, but certainly not impossible. If you are fairly new to weight training and have optimal macros (i.e., enough protein intake) then it may be possible to still log gains in lean body mass. However as you become more conditioned, assuming you stay at your current caloric intake, I would expect the gains in muscle to subside. Because of the concurrent loss of body fat and muscle gain, it would be best if you track you body fat percentage and not just absolute weight to gauge your progress. - M

Thank you for your response. Since I am in this for the longhaul and refuse to give up, I will concentrate more on bodyfat loss than weight.

Thanks
Bob

Water weight is easy to gain.
1800 calories is a good LEAN measurement and as Mhariris says, keep the protein high, keeping the carbs and fat low. But what you are measuring is Water weight changes. I can gain and lose 3 to 4 pounds in one day. Forget the weight scale. forget about 3 weeks measurements. It very good to set short term goals but 3 weeks???
How 'bout 3 months. I want to gain 10 pounds of muscle and lose 10 pounds of fat with a 10% body fat, but I have a 1 YEAR commitment of diet and weight training WITHOUT cardio. Just gotta EAT many times a day and LIFT heavy at low reps.