ABSTRACT
Background A healthy diet in a college student life is critical to ensure their normal growth, study anddevelopment.Aim In order to accurately assess the dietary pattern of college students and guide it, our study aims to evaluatethe validity of instant photography as an alternative dietary assessment method in college students.Methods Nine participants were enrolled and given a presentation on dietary assessment methods, includingweighing, 24-hour recall, and instant photography. The participants took pictures of their foods from three anglesbefore and after eating for constant seven days, foods weighing was completed by others. Then, the participantsrecalled the foods’ weights after 24 hours. Two trained observers estimated food weight from the digital images(n = 285) gathered at the end of the study with the aid of Chinese food atlas reference.Results Instant photograph showed significant correlation with weighing method on food weights of grains,tubers, vegetables, fruits, meat and eggs (all P ≤ 0.01). 24-hour method had similar correlation with weighingmethod on food weights except fruits. Compared with 24-hour recall, instant photograph displayedunderestimation on weights of grains, tubers, vegetables, and meat. However, instant photograph had moreaccurate estimations on weights of fruits and egg. Furthermore, compared with nutrients data from weighingmethod, both instant photography and 24-hour recall methods showed promising estimations on the amounts ofenergy, protein, fat, carbohydrate, vitamin A, vitamin C, vitamin E, calcium, iron and zinc (all P < 0.001). Comparedwith 24-hour recall, instant photograph displayed underestimation on the amounts of energy, protein, fat,carbohydrate, vitamin A, vitamin C, vitamin E, zinc. However, instant photograph had a more accurate estimationon calcium.
ABSTRACT
Mitofusin-2 (Mfn2) gene expression is positively correlated with insulin sensitivity in patients with type 2 diabetes. However,it is unclear if Mfn2 is involved in carbohydrate metabolism and lipid homeostasis. In order to investigate the specific functions of Mfn2 in glycometabolism and lipid homeostasis in BALB/c mice,a RNA interference technique-mediated hydrodynamic injection was developed,in which short hairpin RNAs (shRNAs) were used to inhibit the Mfn2 expression in vivo. Seventy-two mice were randomly divided into two groups:the Mfn2 reduction group (Mfn2/shRNA) and the negative control group (NC). Intraperitoneal glucose tolerance tests and intraperitoneal insulin tolerance tests were used to evaluate glycometabolism and insulin sensitivity.D-(3-3H) glucose or 3H2O was injected into the tail vein or intraperitoneally to facilitate the calculation of the rate of hepatic glucose production and fatty acid synthesis in vivo. The results showed that,in Mfn2/shRNA mice,the liver Mfn2 protein was significantly decreased,and fasting blood glucose concentrations were increased by approximately 48%,when compared with the NC mice. In parallel with the changes in fasting glucose levels,hepatic glucose production was significantly elevated in Mfn2/shRNA mice. When insulin was administrated,these mice exhibited impaired insulin tolerance.It was also found that the reduction of Mfn2 markedly decreased the rate of fatty acid synthesis in the liver,and the Mfn2/shRNA mice exhibited hypertriglyceridema. Taken together,our results indicate that Mfn2 plays an important role in maintaining glucose and lipid homeostasis,and in the development of insulin resistance in vivo.