Obese men underreport their calorie intake by an average of 37 percent

Obese men underreport their calorie intake by an average of 37 percent according to a 2000 study (Goris et al, 2000).

Percent Fat Intake: 46% fat, under-reported as 39% fat

The men ate a diet which contained an average of 46 percent fat but reported eating only 39 percent fat, underreporting the percent fat they ate by 7 percent.

(As noted in the previous story, this brings up the question whether or not fat intake has been reduced as recent surveys have reported.)

It was also noted that the more the men underreported their calorie intake, the more they underreported percent of fat in their diet.

Subjects: 30 obese men, BMI 34, 239 lbs, 44-years-old

The study involved 30 obese men with an average body mass index of 34 with a weight of 239 pounds and an average age of 44-years.

During the week that the men were monitored they lost 2.2 pounds which indicated that they ate 26 percent less than they usually did.

Other studies have found under-reporting of 20-50%

Nine other studies which have used doubly labeled water to accurately determine calorie intake and expenditure have found underreporting of approximately 20 to 50 percent according to the authors of the current study.

They also noted that the degree of underreporting correlates with body mass index.

Previous Study in Lean Women underreported calorie intake by 16% due to under-eating in the study

A previous study found that highly-motivated lean women underreported their calorie intake by 16 percent which was fully explained by undereating during the study (Goris and Westerterp, 1999).

Obese women ate 44% fat, non-obese women 37% fat

Also of interest was that the authors noted that a previous study found that obese women ate a diet containing 44 percent fat compared to 37 percent for non-obese women (Westerterp-Plantenga et al, 1996).

Overweight men and women underreported their calorie intake by at least 16%

The authors also noted that a previous study found that overweight men and women underreported their calorie intake by at least 16 percent in the third National Health and Nutrition Examination Survey (NHANES III) that was conducted to assess the health and nutritional status of the U.S. population.

Most Databases on Food Intake are Wrong Due to Under-Reporting

“It is now freely admitted that most databases do not inform us well about the actual foods that individuals consume because of massive problem of misreporting,” John E. Blundell from the School of Psychology for the University of Leeds in the United Kingdom stated in an accompanying editorial.

25% under-reporting when people are asked to recall what they ate

When people are recalling what they ate, the underreporting of calories is estimated at 25 percent.

Blundell also noted that interviews with people who underreported intake admitted that they had undereaten or underrecorded because they were embarrassed about what they had eaten.

Even people who were not identified as under-reporters admitted to changing food records

Interestingly, even people who were not identified as underreporting admitted to adjusting their food records.

“[Therefore] even the records of those subjects who appear to be ‘above suspicion’ cannot be regarded as safe,” Blundell notes.

“Because food provides one of life’s most accessible and potent forms of pleasure, perhaps we should accept that we are dealing with behavior governed by hedonism rather than by rationality.”

REFERENCE

Goris AHC; Margriet S Westerterp-Plantenga MS; Westerterp KR. Undereating and underrecording of habitual food intake in obese men: selective underreporting of fat intake. Am J Clin Nutr 2000 Jan;71(1):130-4.

Goris AH; Westerterp KR. Underreporting of habitual food intake is explained by undereating in highly motivated lean women. J Nutr 1999 Apr;129(4):878-82.

Westerterp-Plantenga MS; Pasman WJ; Yedema MJ; Wijckmans-Duijsens NE. Energy intake adaptation of food intake to extreme energy densities of food by obese and non-obese women. Eur J Clin Nutr 1996 Jun;50(6):401-7.

Briefel RR; McDowell MA; Alaimo K; Caughman CR; Bischof AL; Carroll MD; Johnson CL. Total energy intake of the US population: the third National Health and Nutrition Examination Survey, 1988-1991. Am J Clin Nutr 1995 Nov;62(5 Suppl):1072S-1080S.

Blundell JE. WHat foods do people habitually eat? A dilemma for nutrition, an enigma for psychology. Am J Clin Nutr 2000 Jan;71(1):3-5.

Articles on the same subject can be found here:

• Calorie intake, Underreporting