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Energy Balance, Obesity and Type-2 Diabetes

  1. M Daniel Lane

Published Online: 15 MAR 2009

DOI: 10.1002/9780470015902.a0021317

eLS

eLS

How to Cite

Daniel Lane, M. 2009. Energy Balance, Obesity and Type-2 Diabetes. eLS. .

Author Information

  1. Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

Publication History

  1. Published Online: 15 MAR 2009

Abstract

Energy balance is determined by caloric intake versus caloric expenditure. Complex control systems promote energy storage (primarily as adipose tissue fat) during periods of food surplus and mobilization of energy stores when food is scarce. These regulatory systems operate both locally within cells and between different body tissues and are mediated by circulating hormones and direct neural connection from the central nervous system to peripheral tissues. In modern society where lifestyles have shifted towards the excessive consumption of palatable ‘high energy’ foods and a sedentary life, these control mechanisms can be circumvented and in so doing lead to obesity and its pathological consequences. Prominent among these consequences are insulin resistance, i.e. the inability of cells to respond normally to insulin, and Type-2 diabetes. Approximately 30% of the inhabitants of the United States meet the criteria for obesity.

Key concepts

  • Animals possess complex control systems with which to regulate energy storage and expenditure.

  • The concept of energy balance.

  • How is blood glucose level regulated?

  • How do changes in blood glucose level alter the secretion of hormones that regulate energy metabolism?

  • What are the major physiological fuels that provide energy for different cell types and how do changes in hormone level affect fuel production and utilization?

  • Nature of interplay between tissues/organs through the production and utilization of circulating physiological fuels.

  • What is insulin resistance and what are its consequences?

  • What constitutes the obese state and how does obesity lead to insulin resistance and Type-2 diabetes?

  • how adipocytes develop from stem cells and the consequences of adipocyte hyperplasia.

  • How does persistent obesity lead to failure of the insulin-secreting pancreatic β-cell and the diabetic state?

Keywords:

  • fat;
  • insulin;
  • glucagons;
  • body mass index;
  • β-cell