Sixteen diet-induced obese (DIO – fed Research Diets, Inc. D12492i, 60% calories as fat = “HFD”), and sixteen control diet fed (Research Diets, Inc. D12450Bi, 10 % calories as fat = “CON”) C57BL/6J-male mice were obtained at 18 weeks of age from the Jackson Laboratory (Bar Harbor, ME). These animals had been fed these respective diets since 6 weeks of age. Individually housed animals from both diet groups were randomized to remain on the ad-lib diets (DIO-AL and CON-AL) or to be calorically restricted to decrease their body weight by ~20% over a 1–2 week period by twice daily feeding of reduced quantities (50% of ad-libitum intake) of their respective diets. After a 20 ±1% weight reduction, weight-reduced (DIO-WR and CON-WR) mice were provided calories sufficient to stabilize their weights for an additional 23 weeks. Nine weeks after initiation of the weight reduction protocol (Figure 1A , denoted day 0), body weights (daily for all mice) and food intake (FI; daily for WR and every two days for AL mice) were recorded for the next 93 days, except on days when mice were in the calorimeter. Metabolizable energy intake (MEI), defined as grams of food ingested per 24h (weighed using custom-made stainless steel feeding baskets that minimized spillage - Dieter Wenzel; Detmold, Germany) multiplied by the metabolizable energy for the respective diets (5.24 Kcal/g for high fat (HFD) and 3.85 Kcal/g for the control (CON) diet), was calculated from the FI measurements. The first day of this 93 day period is designated as day 0 (Figure 1A ). The 93 days following day 0 are divided into 3 measurement periods (Figure 1A ):
One DIO-AL mouse died during the study and data from one CON-AL mouse were not included due to malfunction of the calorimetry chamber. Aspects of this study have been described previously 7 . All protocols were approved by the Columbia University Institutional Animal Care and Use Committee.
On day 0, day 37, and following each 72-hour calorimetry period, body composition was determined using a Bruker Minispec mouse TD-NMR analyzer (Bruker Inc, Billerica MA) 8 (link). All body composition measurements were made at 8–9 am, before weight reduced animals were fed.
One DIO-AL mouse died during the study and data from one CON-AL mouse were not included due to malfunction of the calorimetry chamber. Aspects of this study have been described previously 7 . All protocols were approved by the Columbia University Institutional Animal Care and Use Committee.
On day 0, day 37, and following each 72-hour calorimetry period, body composition was determined using a Bruker Minispec mouse TD-NMR analyzer (Bruker Inc, Billerica MA) 8 (link). All body composition measurements were made at 8–9 am, before weight reduced animals were fed.