Energy Expenditure

EE: Thermic Effect of Food: Fasting (2005-2006)

Thermic Effects of Food, Snacks and Alcohol

  • Thermic Effects of Food Peaks
  • Fasting Period Necessary to Avoid Resting Metabolic Rate Measurement Error
  • Alcohol Effects on Resting Metabolic Rate
The increases in metabolic rate associated with the digestion, absorption, and metabolism of dietary nutrients in referred to as the thermic effect of feeding (TEF).  There are several approaches to reporting RMR increases associated with the absorption, transport, and conversion into substrate storage of food energy and how it is distributed over time.  The results are dependent on the planned  measurement duration of the research study.  In the evidence analysis, one study (Reed GW, 1996) quantified RMR increases over a 6-hour measurement interval after consuming 650-1394 kcals (mean 945 kcals/test meal) and provided substantial guidance when defining how to report  the "total" thermic effect of feedings.  For example, over a 3-hour measurement inerval, 57% of the total TEF had been expended.  Over 4-hour and a 5-hour measurement intervals, 77% and 91% of the total thermic effect of feeding had been expended.   Therefore, Expert Panel members identified that a 5-6 hour measurement interval, most accurately reflected the total thermic effect of feeding (e.g., meal or snack test) that is commonly referred to "diet-induced thermogenesis."  The energy increases.