(A–F) Chow-fed Balb/c mice (10-week-old males) were housed 4 mice per cage and injected i.p. with 100 μl PBS in the absence or presence of rLIF or rLIF K159A at 80 μg/kg body weight twice daily throughout the experiment. Body weight (A), food intake (B), and ECHO MRI measurements of fat mass (C) and lean mass (D) were measured at 9 a.m. at the indicated time points. Body weight, fat mass, and lean mass are shown relative to the average day 0 reference value for each respective cohort. The average values for body weight (A) at day 0 were 21.3, 21.8, and 22.3 g for the PBS-, rLIF-, and rLIF K159A–treated mice, respectively. The average values for fat mass (C) at day 0 were 2.4, 3.1, and 3.1 g for the PBS-, rLIF-, and rLIF K159A–treated mice, respectively. The average values for lean mass (D) at day 0 were 16.1, 16.3, and 16.5 g for the PBS-, rLIF-, and rLIF K159A–treated mice, respectively. Each value represents mean ± SEM of 4 mice. (E and F) Epididymal white adipose tissue (eWAT), gastrocnemius muscle, liver, and spleen were harvested 21 days after start of injections. Representative sections stained with H&E (E) of each of these tissues are shown. Magnification, 40×; scale bar: 270 μm. Additionally, eWAT from 2 representative mice from each cohort was processed, and aliquots of cell lysate (15 μg/lane) were subjected to IB analysis (F) with the indicated antibodies as described in Methods. (A–F) These results were confirmed in at least 3 independent experiments. *P < 0.05 and **P < 0.01 based on Student’s t test (B) or P value based on use of Generalized Estimating Equation approach comparing multiple groups over time with rLIF-treated mice as the reference value (A, C, and D).