1. A review of methodology, variables and data presentation
Thermic Effect of Food
A review of methodology, variables and data presentation

2. What is the thermic effect of food (TEF). What variables affect TEF
What is the thermic effect of food (TEF)? What variables affect TEF? How is TEF measured? How is data displayed?

3. Outline Thermic effect of food Review History of methodology
Weststrate, 1990
Reed, 1996
Current methodology
Wilms, 2013
Mansour, 2012
Du, 2014
Conclusion
References

4. Outline Review thermic effect of food History of methodology
Weststrate, 1990
Reed, 1996
Current methodology
Wilms, 2013
Mansour, 2012
Du, 2014
Conclusion
References

5. Thermic Effect of Food
TEF is the increase in energy expenditure after eating
Composes about 10% of total energy
It includes the energy used for the
Consumption of food
Transportation of nutrients
Digestion of nutrients
Storage of excess fuel

6. Thermic Effect of Food Variables that effect TEF include: Meal size
Meal composition
Gender
Age
Body composition
Glucose/insulin responses
Reappraisal, palatability,
De Jonge- review of 29 studies, most say there is a difference

7. Outline History of methodology Review thermic effect of food
Weststrate, 1990
Reed, 1996
Current methodology
Wilms, 2013
Mansour, 2012
Du, 2014
Conclusion
References

8. There is a variation in methodology!
Instruments used in measuring RMR
Study protocols
Length of total measurement time
Measured and break schedule
State of activity allowed
Choice of subjects
Test meal composition
Size of the test meal
Meal size based on initial weight
Mixed population
Gender- exclude men
How should they control for size/gender/population?

9. Weststrate, 1993
Resting metabolic rate and diet induced thermogenesis: A methodological reappraisal Am J Clin Nutr

10. Methodology- Weststrate, 1993
Obtain a valid RMR- fasting 12 hrs, rest time varied
Give patient the meal- delivery of meal
Measure metabolic rate for 3-4 hours
Avg metabolic rate every 5 minutes
Avg metabolic rate for every hour
Subtract metabolic rate avg from base RMR to get DIT
Allow patient to move every hour for 2-3 minutes during calibration
Reappraisal

11. TEF displayed as kJ/min Meal size variable
Reappraisal

12. Methodology- Weststrate
Controversies to methodology
4 hour time period leads to large intra-individual variability
Total DIT is not being shown in 4 hours
Thermogenic response to food: intra-individual variability and measurement reliability- 6 hours
Measuring the thermic effect of food- Reed hours

13. Measuring the thermic effect of food Am J Clin Nutr
Reed, 1996
Measuring the thermic effect of food
Am J Clin Nutr

14. Methodology- Reed, 1996 Obtain a valid RMR- hood Give patient the meal
Measure metabolic rate for 10 minutes every half hour for 6 subsequent hours
Measurements record same was as method 1
Subjects could relax and use the restroom
Meal size- Measuring the thermic effect of food- reed 1996

15. Results- Reed, 1996 Sample TEF TEF displayed as kJ/h above RMR
6hr mark

16. TEF displayed as % of meal size Increase time=increased accuracy
Total measuring time
TEF displayed as % of meal size
Increase time=increased accuracy
TEF as %meal size= Kcals burned above RMR divided by the kcals from the meal
Calculated % meal size for hour 3, 4, 5 and 6
Subtracted % meal hour 3, 4, and 5 from % meal for hour 6
=hour 3: big difference in kcals burn for TEF
=hour 4:
=hour 5: similar in kcals burn for TEF
=the longer the time, the more accurate the results
Example: burned 20% meal at hour 6, 17% meal at hour 5, 14% meal at hour 4, 10% meal at hour 3

17. Reed, 1996 Variables that affect TEF
As seen in Figure 6, the peak of the TEF curve moves up as meal size and the subject’s FFM increase. The peak is related positively to meal size and negatively to meal size squared in the same way as for the total TEF. This nonlinear relation to meal size indicates that the peak increases with meal size, then reaches a saturation level. The new factor here is that peak TEF is inversely related to percent body fat of the subject.
Peak energy and time to peak- emphasize that!
Meal composition- of higher fat

18. Meal size- Measuring the thermic effect of food- reed 1996
*this slide is an illistration of meal size- some is controversial
Slow down and point things out
Height of peak AND time to peak- point out the differences
Delayed insulin response to cause the delayed peak

19. Outline Current methodology Review thermic effect of food
History of methodology
Weststrate, 1990
Reed, 1996
Current methodology
Wilms, 2013
Mansour, 2012
Du, 2014
Conclusion
References

20. Wilms, 2013
Enhanced thermic effect of food after Roux- en-Y gastric bypass surgery
J Clin Endocrinol Metab

21. Wilms, 2013
Compares REE in lean, obese, and post-gastic bypass women (10 per group) of similar age and gender
Does gastric bypass surgery affect resting energy expenditure and TEF?
What is the relationship between TEF and postprandial insulin secretion?

22. Methodology- Wilms, 2013 Obtain a valid RMR (20 mins)- hood
Meal served
containing 39 g carbs, 15 g prot, and 3 g fat (246 kcal) in Protiline balance (ensure-like drink)
Indirect calorimeter was measured for 90 minutes
Two 30 minute measurements with a 30 minute break. Metabolic rate averaged every ten minutes.
During break- patients stayed in a resting state

23. Gastric bypass increased peak and decreased time to peak
TEF measured as kJ/min
Gastric bypass increased peak and decreased time to peak
Increased for 30 mins in gastric ladies
RYGB (black columns)
severely obese (gray columns)
lean (open columns)
*, P < .01; **, P < .001

24. Results
TEF area under curve (0–90 minutes) was significantly greater in gastric bypass patients than in severely obese and lean women (both P < .01)
Gastric bypass surgery is correlated with increased postprandial rise in glucose, insulin, and C-peptide levels (all P < .001)
After ingestion of the mixed meal, the RQ increased to significantly greater values in the RYGB patients than in the severely obese and lean group (P < .001 for ANOVA time × group interaction)

25. Mansour, 2012
Ginger consumption enhances the thermic effect of food and promotes feelings of satiety without affecting metabolic and hormonal parameters in overweight men
Metabolism

26. Mansour, 2012 Compares ginger’s affects on overweight men (BMI 25-29)
Will ginger consumption affect TEF and satiety?
Does ginger alter appetite-regulating hormones and inflammatory markers?

27. Methodology, Mansour Obtain a valid RMR (30 mins)- chamber
Meal served- 15 mins to consume
standard breakfast:
5 small corn muffins: 525 kcal, 67.5 g carb, 25 g fat, 7.5 g prot
orange juice: 70 kcal, 17.0 g carb,
6 oz. of hot water
Indirect calorimeter was measured for 6 hours for 40 minutes/h
The first ten minutes of each measuring period was discarded for stabilization purposes
*ginger

28. Black- with ginger white- without ginger
TEF displayed as % increase over RMR
TEF increase 42.7kcal/d with ginger
Black- with ginger white- without ginger

29. Results
There was a significant effect of ginger on TEF (ginger vs control = 42.7 ± 21.4 kcal/d, P = .049)
The area under the curve was not different (P = .43)
There were no effects of ginger on glucose, insulin, lipids, or inflammatory markers

30. The Thermic Effect of Food is Reduced in Older Adults Horm Metab

31. Du, 2014 Compare age’s affects on TEF in 209 men and women
Does age affect RMR and TEF and if so, how?
What is the relationship between body composition, fat distribution and postprandial insulin responses and measured TEF?
The Thermic Effect of Food is Reduced in Older Adults
S. Du1, 2, *, T. Rajjo2, *, S. Santosa3, M. D. Jensen2

32. Methodology- Du, 2014 Obtain a valid RMR (30 mins)-hood Meal served
33% of daily calories (from Ensure) calculated according to REE
Participants were then allowed to get out of bed to use the bathroom
Indirect calorimeter was measured hourly for 4 hours
Each reading included a 5 minute stabilization period, followed by a 15min reading

33. TEE displayed as kcal/min TEF (TEE-REE) displayed as kcal/min
Age adjusted for FFM
Older adults had reduced RMR and TEF
Controlled for varying age by adjusting RMR for FFM using a univariate regression analysis
[Fig. 2] shows the curve of the rate of oxygen consumption (VO2), carbon dioxide production (VCO2), the respiratory exchange ratio (RER), TEE, and TEF in the older adults and youngs. The peak postprandial VO2 (60 min) was significantly greater in young than older adults (p<0.05) and the RER was greater from basal to 180 min in young than the older adults (p<0.01), indicating the young oxidize more carbohydrate as a source of energy. The postprandial TEE was greater in young than older adults (p<0.05 at 60 and 240 min, p<0.01 at 120 min) and the TEF was greater in young than older adults (p<0.05 at 60, 120 and 240 min).

34. Divde TEF over meal size

35. Results
BMR after being adjusted for FFM was less in older adults (p=0.01)
TEF food was ̴ 1% less in the older adults (p=0.02)
After controlling for meal size and FFM, body fat and fat distribution did not predict TEF
Both BMR and TEF are less in older adults, even when they have similar amounts of lean tissue and consume a similar size meal

36. Outline Conclusion Review thermic effect of food
History of methodology
Weststrate, 1990
Pier, 1992
Reed, 1996
Current methodology
Wilms, 2013
Mansour, 2012
Du, 2014
Conclusion
References

37. Conclusion
Methodology varies between studies (instrument, schedules, meal)
If measuring full TEF= 4-6 hours
Ways to display results: *
Total TEE (avg kcal per min/h, total area under the curve)
Total TEF (avg kcal per min/h, total area under the curve)
% increase over RMR
Peak energy or time to peak
TEF % meal
Known variables that effect TEF:
Meal size
Body composition
Gender
Age
Glucose/Insulin responses
Control for varying characteristics (BMI, age, gender, body composition) of participants by choosing similar participants or through regression analysis
Control for meal size by standardizing the meal or by displaying TEF effect as % of meal in kcals
**how interpret results will depend on how results are presented (time frame, varibles adjusted)

38. References
Westrate, J. Resting metabolic rate and diet induced thermogenesis: A methodological reappraisal. Am J Clin Nutr November 1993 vol. 58 no
Reed GW, Hill, JO. Measuring the thermic effect of food. Am J Clin Nutr February 1996 vol. 63 no
Wilms B, Ernst B, Schmid SM, Thurnheer M, Schultes B. Enhanced thermic effect of food after Roux-en-Y gastric bypass surgery. J Clin Endocrinol Metab Sep;98(9): Epub 2013 Jul 3.
Mansour MS, Ni YM, Roberts AL, Kelleman M, Roychoudhury A, St-Onge MP. Ginger consumption enhances the thermic effect of food and promotes feelings of satiety without affecting metabolic and hormonal parameters in overweight men: a pilot study. Metabolism Oct;61(10): Epub 2012 Apr 24.
Du S, Rajjo T, Santosa S, Jensen MD. The Thermic Effect of Food is Reduced in Older Adults. Horm Metab Res 2014; 46(05):