Does an increased intake of added sugar affect appetite in overweight or obese adults, when compared with lower intakes? A systematic review of the literature.

Changes in added sugar intake have been associated with corresponding changes in body weight. Potential mechanisms, particularly the impact of added sugar intake on appetite, warrant exploration. A systematic literature review of randomised controlled trials investigated the association between added sugar consumption and appetite in overweight and obese adults. A systematic search of Medline, Cochrane CENTRAL, Web of Science and CINAHL included studies that examined the relationship between added sugar intake and appetite markers, in comparison with a group with lower added sugar intake. A total of twenty-one articles describing nineteen studies were included in the review. The effect of added sugar on appetite was explored separately by reported comparisons of added sugar type and their effect to three study outcomes: energy consumption (n 20 comparisons); satiety (n 18); and appetite hormones, leptin (n 4) or ghrelin (n 7). Increased added sugar consumption did not impact subsequent energy intake (n 9), nor did it influence satiety (n 12) or ghrelin levels (n 4). Differences in the total daily energy intake were comparable with the differences in energy values of tested products (n 3). Added sugar intake was reported to increase leptin levels (n 3). This review did not find a consistent relationship between added sugar intake and appetite measures, which may be partially explained by variations in study methodologies. There is a need for randomised controlled trials examining a range of added sugar sources and doses on appetite in overweight and obese adults to better understand implications for weight gain.

Pork and Chicken Meals Similarly Impact on Cognitive Function and Strength in Community-Living Older Adults: A Pilot Study.

A pilot quasi-experimental study investigated whether provision of pork, a rich source of thiamin, as the main protein source in meals four times/week for 12 weeks resulted in improved muscle mass, body strength, and cognitive function in community-living older adults compared to similar meals containing chicken. Retirement villages were randomized to receive pre-prepared frozen meals containing either pork or chicken. Dietary intake was assessed by three-day food records and cognitive domains assessed using validated tests. Hand grip strength was measured and lower extremity performance assessed by the sit-to-stand test, get-up-and-go test and six-minute walk test. Forty-eight volunteers participated (78.2 ± 6.2 y). In linear mixed models, controlling for baseline physical activity and dietary protein and energy intake, no differences were found between pork (n = 19) and chicken (n = 12) groups. The chicken group had improved Rey Auditory Verbal Learning test scores (verbal learning and memory) at six weeks (p < 0.001). Provision of four pork meals a week did not result in improvements in cognitive function, nor measures of strength or physical function, compared to those receiving chicken meals in healthy older adults. This suggests that merely changing the type of dietary protein provided by meat does not impact physical or cognitive function.