I wouldnt try to lose weight while in treatment its just so hard while I was in treatment I went on low carb Atkins thing and lost 79 pounds just to see it come back after I lightened up on the strictly 20% carbs went up to about 30% and it all came back.Its just to many battles on to many fronts.

Sugestion maintain what you have now weight wise and when your better from lyme then attack it.

Good Luck

ps Before lyme took me apart I used to be 210lbs of inshape lean muscled ateries showing over them tight sixpack 500 situps every other day and walked 5to6 miles 3 times a week for maintenance because I have been on the heavy side all my life.
Now I start all over at 46yrs old so maintenance is the key if you can do it just maintain the gain you have now.

Then, I started to really notice symptoms of hypothyroid and was tested. Was borderline high on TSH (indicating low thyroid) I certainly wasn't metabolizing well at all. Gained 20 pounds that 1 year, even panic-dieted through it and I didn't stop gaining. Then I just had to give a rest. I gave up cause I was just to sick to try any longer.

Now, with treatment, my thyroid is (luckily) more in the normal range again after 5 years of being sluggish.

I agree with treepatrol, it's too much for most of us to get well and undertake dieting, especially if your thyroid has been affected by lyme like I believe mine was. I tried to diet and even exercise when I was the symptomatic, but I just gave up after one year of that madness because nothing was happening (weight loss) Yes, it was demoralizing!! I felt so out of control in all areas.

Now that I'm feeling great, I'm on an mild exercise program, on a reasonable diet and actually losing, although VERY SLOWLY, much slower than before being lymed. But at least it's something. The weight gain is bigger than I've ever had to deal with before so I can't crash diet it away; I'm trying to convince myself to take it very slowly.

Unfortunately, weight gain is a problem for many of us...I've seen lots of threads like your over the last 20 months.