Wearable Food Intake Monitoring Technologies: A Comprehensive Review

The ability to resist the urge to eat requires the proper functioning of neuronal circuits involved in top-down control to oppose the conditioned responses that predict reward from eating the food and the desire to eat the food. Imaging studies show that obese subjects might have impairments in dopaminergic pathways that regulate neuronal systems associated with reward sensitivity, conditioning and control. It is known that the neuropeptides that regulate energy balance (homeostatic processes) through the hypothalamus also modulate the activity of dopamine cells and their projections into regions involved in the rewarding processes underlying food intake. It is postulated that this could also be a mechanism by which overeating and the resultant resistance to homoeostatic signals impairs the function of circuits involved in reward sensitivity, conditioning and cognitive control. Published by Elsevier Ltd.

Epidemiologic studies report inconsistent findings on the association of fruit and vegetable intake with the risk of cardiovascular disease. The objective was to examine the relation between fruit and vegetable intake and the risk of cardiovascular disease. We studied 9608 adults aged 25-74 y participating in the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study and free of cardiovascular disease at the time of their baseline examination between 1971 and 1975. Fruit and vegetable intake at baseline was measured with a food-frequency questionnaire. The incidence of and mortality from cardiovascular disease were obtained from medical records and death certificates. Over an average of 19 y, 888 strokes (218 fatal), 1786 ischemic heart disease events (639 fatal), 1145 cardiovascular disease deaths, and 2530 all-cause deaths were documented. Consuming fruit and vegetables > or = 3 times/d compared with <1 time/d was associated with a 27% lower stroke incidence [relative risk (RR): 0.73; 95% CI: 0.57, 0.95; P for trend = 0.01), a 42% lower stroke mortality (0.58; 0.33, 1.02; P for trend = 0.05), a 24% lower ischemic heart disease mortality (0.76; 0.56, 1.03; P for trend = 0.07), a 27% lower cardiovascular disease mortality (0.73; 0.58, 0.92; P for trend = 0.008), and a 15% lower all-cause mortality (0.85; 0.72, 1.00; P for trend = 0.02) after adjustment for established cardiovascular disease risk factors. We showed an inverse association of fruit and vegetable intake with the risk of cardiovascular disease and all-cause mortality in the general US population.

Development of the doubly-labeled water method has made it possible to test the validity of dietary intake instruments for the measurement of energy intake. Comparisons of measured energy expenditure with energy intake from either weighed or estimated dietary records against energy expenditure have indicated that obese subjects, female endurance athletes, and adolescents underestimate habitual and actual energy intake. Individual underestimates of 50% are not uncommon. Even in non-obese adults, where bias is minimal, the standard deviation for individual errors in energy intake approaches 20%. Two investigations of the validity of self-reported dietary records for measuring change in dietary intake also indicate large underestimates of the actual change. Because of bias and imprecision, self-reported energy intakes should be interpreted with caution unless independent methods of assessing their validity are included in the experimental design.