I'll second what Lindsay said. 800 calories is very low for your weight (at ~170lbs your body needs about 1600 calories a day just to live off of even if you are very sedentary). Your brain needs fuel to think (and resist temptation!) and if you eat too few calories too long your body will start to break down muscle as well as fat (you don't want to lose muscle!). I think that prepackaged meals can be a great starting point for someone who is on a budget and needs help with portion control, but do try to get some fresh fruits and vegetables in there as well. Good luck!
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