A historical study led to the hypothesis that appetite is homeostatically controlled when physical activity level is high but this control is lost at lower energy expenditure. This paradigm of an asymmetric control of energy balance with a “regulated zone” at high energy expenditure and an “unregulated zone” at low energy expenditure is incompletely verified because it requires a fixed energy balance at different levels of energy expenditure, a condition that can be investigated under strictly controlled conditions. We therefore investigated the impact of energy turnover (ET) on the regulation of energy balance and glucose metabolism in a highly controlled nutritional intervention study in a metabolic chamber. We found out that ET improves appetite control, glucose metabolism and energy partitioning. These results were confirmed with overfeeding and caloric restriction and were thus independent of energy balance. In contrast to the prevailing concept of body weight control, the positive impact of physical activity is not simply explained by burning up more calories but, at certain volumes, also involves improving appetite control. Importantly, for prevention of weight gain a PAL of 1.76 does not require vigorous physical activity or exercise but can be obtained by low-intensity physical activity.

Hägele FA, Büsing F, Nas A, Hasler M, Müller MJ, Blundell JE, Bosy-Westphal A.

Appetite Control Is Improved by Acute Increases in Energy Turnover at Different Levels of Energy Balance. J Clin Endocrinol Metab. 2019 Oct 1;104(10):4481-4491. doi: 10.1210/jc.2019-01164.

Nas A, Büsing F, Hägele FA, Hasler M, Müller MJ, Bosy-Westphal A. Impact of energy turnover on fat balance in healthy young men during energy balance, caloric restriction and overfeeding. Br J Nutr. 2019 Oct 11:1-27. doi: 10.1017/S0007114519002551

Büsing F, Hägele FA, Nas A, Hasler M, Müller MJ, Bosy-Westphal A. Impact of energy turnover on the regulation of glucose homeostasis in healthy subjects. Nutr Diabetes. 2019 Aug 8;9(1):22. doi: 10.1038/s41387-019-0089-6.

There is a need for non-invasive and inexpensive body composition technology for clinical studies. Bioelectrical impedance analysis (BIA) was long been judged as inaccurate and indirect approach for body composition analysis. We improved the prediction and validation of body composition by tetrapolar 8-electrode BIA and provided reference values for BIA raw data that can be used in clinical studies.

Bosy-Westphal A, Jensen B, Braun W, Pourhassan M, Gallagher D, Müller MJ. Quantification of whole-body and segmental skeletal muscle mass using phase-sensitive 8-electrode medical bioelectrical impedance devices. Eur J Clin Nutr. 2017 Sep;71(9):1061-1067. doi: 10.1038/ejcn.2017.27.

Bosy-Westphal A, Schautz B, Later W, Kehayias JJ, Gallagher D, Müller MJ. What makes a BIA equation unique? Validity of eight-electrode multifrequency BIA to estimate body composition in a healthy adult population. Eur J Clin Nutr. 2013 Jan;67 Suppl 1:S14-21. doi: 10.1038/ejcn.2012.160.

Bosy-Westphal A, Danielzik S, Dörhöfer RP, Later W, Wiese S, Müller MJ. Phase angle from bioelectrical impedance analysis: population reference values by age, sex, and body mass index. JPEN J Parenter Enteral Nutr. 2006 Jul-Aug;30(4):309-16. doi: 10.1177/0148607106030004309.

Bosy-Westphal A, Danielzik S, Dörhöfer RP, Piccoli A, Müller MJ. Patterns of bioelectrical impedance vector distribution by body mass index and age: implications for body-composition analysis. Am J Clin Nutr. 2005 Jul;82(1):60-8. doi: 10.1093/ajcn.82.1.60.

Partitioning between fat and lean mass contributes to body weight regulation as well as metabolic risk. The impact of carbohydrates on the gain in fat mass (i.e. the carbohydrate-insulin model of obesity) and intermittent fasting is still under debate. We investigated the impact of diet on fuel partitioning and found out that both, breakfast skipping and a high glycemic load adversely affected metabolic flexibility and macronutrient balance.

Nas A, Mirza N, Hägele F, Kahlhöfer J, Keller J, Rising R, Kufer TA, Bosy-Westphal A. Impact of breakfast skipping compared with dinner skipping on regulation of energy balance and metabolic risk. Am J Clin Nutr. 2017 Jun;105(6):1351-1361. doi: 10.3945/ajcn.116.151332.

Bosy-Westphal A, Hägele F, Nas A. Impact of dietary glycemic challenge on fuel partitioning. Eur J Clin Nutr. 2017 Mar;71(3):327-330. doi: 10.1038/ejcn.2016.230.

Kahlhöfer J, Karschin J, Silberhorn-Bühler H, Breusing N, Bosy-Westphal A. Effect of low-glycemic-sugar-sweetened beverages on glucose metabolism and macronutrient oxidation in healthy men. Int J Obes (Lond). 2016 Jun;40(6):990-7. doi: 10.1038/ijo.2016.25.

Kahlhöfer J, Lagerpusch M, Enderle J, Eggeling B, Braun W, Pape D, Müller MJ, Bosy-Westphal A. Carbohydrate intake and glycemic index affect substrate oxidation during a controlled weight cycle in healthy men. Eur J Clin Nutr. 2014 Sep;68(9):1060-6. doi: 10.1038/ejcn.2014.132.

Weight regain after weight loss is still a major problem of obesity treatment and individual propensity may depend on the decrease in metabolic rate that was traditionally normalized for changes in fat-free mass or fat mass only. We investigated metabolic adaptation to weight loss and found that adaptive thermogenesis is a rapid phenomenon that is evident already at the beginning of weight loss and is in part independent of changes in organ and tissue masses and is a risk factor for weight regain.

Müller MJ, Enderle J, Pourhassan M, Braun W, Eggeling B, Lagerpusch M, Glüer CC, Kehayias JJ, Kiosz D, Bosy-Westphal A. Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited. Am J Clin Nutr. 2015 Oct;102(4):807-19. doi: 10.3945/ajcn.115.109173.

Bosy-Westphal A, Kahlhöfer J, Lagerpusch M, Skurk T, Müller MJ. Deep body composition phenotyping during weight cycling: relevance to metabolic efficiency and metabolic risk. Obes Rev. 2015 Feb;16 Suppl 1:36-44. doi: 10.1111/obr.12254.

Bosy-Westphal A, Schautz B, Lagerpusch M, Pourhassan M, Braun W, Goele K, Heller M, Glüer CC, Müller MJ. Effect of weight loss and regain on adipose tissue distribution, composition of lean mass and resting energy expenditure in young overweight and obese adults. Int J Obes (Lond). 2013 Oct;37(10):1371-7. doi: 10.1038/ijo.2013.1.

Bosy-Westphal A, Kossel E, Goele K, Later W, Hitze B, Settler U, Heller M, Glüer CC, Heymsfield SB, Müller MJ. Contribution of individual organ mass loss to weight loss-associated decline in resting energy expenditure.  Am J Clin Nutr. 2009 Oct;90(4):993-1001. doi: 10.3945/ajcn.2008.27402.