which would have a more difficult time maintaining body weight at a cooler tempertature a mouse on a diet including ptu and a mouse on a regular diet
Since this is not my area of expertise, I searched Google under the key words "PTU" to get this:
http://www.google.com/search?client=safari&rls=en&q=ptu&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.