1.
A randomized 3-way crossover study indicates that high-protein feeding induces de novo lipogenesis in healthy humans.
Charidemou, E, Ashmore, T, Li, X, McNally, BD, West, JA, Liggi, S, Harvey, M, Orford, E, Griffin, JL
JCI insight. 2019;(12)
Abstract
BACKGROUNDDietary changes have led to the growing prevalence of type 2 diabetes and nonalcoholic fatty liver disease. A hallmark of both disorders is hepatic lipid accumulation, derived in part from increased de novo lipogenesis. Despite the popularity of high-protein diets for weight loss, the effect of dietary protein on de novo lipogenesis is poorly studied. We aimed to characterize the effect of dietary protein on de novo lipid synthesis.METHODSWe use a 3-way crossover interventional study in healthy males to determine the effect of high-protein feeding on de novo lipogenesis, combined with in vitro models to determine the lipogenic effects of specific amino acids. The primary outcome was a change in de novo lipogenesis-associated triglycerides in response to protein feeding.RESULTSWe demonstrate that high-protein feeding, rich in glutamate, increases de novo lipogenesis-associated triglycerides in plasma (1.5-fold compared with control; P < 0.0001) and liver-derived very low-density lipoprotein particles (1.8-fold; P < 0.0001) in samples from human subjects (n = 9 per group). In hepatocytes, we show that glutamate-derived carbon is incorporated into triglycerides via palmitate. In addition, supplementation with glutamate, glutamine, and leucine, but not lysine, increased triglyceride synthesis and decreased glucose uptake. Glutamate, glutamine, and leucine increased activation of protein kinase B, suggesting that induction of de novo lipogenesis occurs via the insulin signaling cascade.CONCLUSIONThese findings provide mechanistic insight into how select amino acids induce de novo lipogenesis and insulin resistance, suggesting that high-protein feeding to tackle diabetes and obesity requires greater consideration.FUNDINGThe research was supported by UK Medical Research Council grants MR/P011705/1, MC_UP_A090_1006 and MR/P01836X/1. JLG is supported by the Imperial Biomedical Research Centre, National Institute for Health Research (NIHR).
2.
Association between maternal nonresponsive feeding practice and child's eating behavior and weight status: children aged 1 to 6 years.
Shi, C, Li, N, Dong, J, Wang, L, Li, X, Ji, C, Wang, X, Chi, X, Guo, X, Tong, M, et al
European journal of pediatrics. 2017;(12):1603-1612
Abstract
UNLABELLED The purposes of this study are to investigate the prevalence of nonresponsive feeding practice (NRFP) and child's eating behavior (CEB) and to explore the hypothetical association between child's weight status, NRFP and CEB for 1- to 6-year-old children. In this study, 2423 caregivers of 1- to 6-year-old children are from the Nanjing Maternal and Child Health Hospital who completed the self-report questionnaires about their NRFP and CEB as well as their children's sociodemographic data. Chi-square test and multiple regression analyses were used to examine the correlation between child's weight status and NRFP and CEB. The total prevalence of overweight and obesity was 15.2 and 7.3%, respectively. High prevalence of CEB problems and NRFP was detected at 2- and 5-year-old children. Moreover, maternal NRFP was significantly positively associated with CEB. The regression and correlation analysis revealed CEB and maternal NRFP are closely associated with BMI. For instance, refusing new food (OR = 3.57, 95%CI, 1.37-9.33, 1.5-year-old) and restriction (OR = 3.01, 95%CI, 1.34-6.76) are likely to be associated with underweight. Preferring junk food (OR = 4.892, 95%CI, 1.71-14.01, 1-year-old) and inattention (OR = 2.24, 95%CI, 1.16-4.35, 1-year-old) are prone to be overweight and obese, and pressure (OR = 0.23, 95%CI, 0.06-0.91, 1-year-old) is less likely to be associated with underweight. CONCLUSION The findings provide strong evidence for the correlation between NRFR and CEB, and this indicates that prevention and intervention of unhealthy weight should start in early life. However, further research is necessary to gain an understanding of the impact of NRFP on CEB and weight. What is known: • Responsive feeding practice is crucial to the formation of eating behavior, and poor practice is associated with the current epidemics of childhood obesity and underweight. What is new: • The findings provide a strong evidence for the correlation between NRFR and CEB. • This finding indicates that NRFR and CEB are associated with child's unhealthy weight.
3.
Reward sensitivity predicts ice cream-related attentional bias assessed by inattentional blindness.
Li, X, Tao, Q, Fang, Y, Cheng, C, Hao, Y, Qi, J, Li, Y, Zhang, W, Wang, Y, Zhang, X
Appetite. 2015;:258-64
Abstract
The cognitive mechanism underlying the association between individual differences in reward sensitivity and food craving is unknown. The present study explored the mechanism by examining the role of reward sensitivity in attentional bias toward ice cream cues. Forty-nine college students who displayed high level of ice cream craving (HICs) and 46 who displayed low level of ice cream craving (LICs) performed an inattentional blindness (IB) task which was used to assess attentional bias for ice cream. In addition, reward sensitivity and coping style were assessed by the Behavior Inhibition System/Behavior Activation System Scales and Simplified Coping Style Questionnaire. Results showed significant higher identification rate of the critical stimulus in the HICs than LICs, suggesting greater attentional bias for ice cream in the HICs. It was indicated that attentional bias for food cues persisted even under inattentional condition. Furthermore, a significant correlation was found between the attentional bias and reward sensitivity after controlling for coping style, and reward sensitivity predicted attentional bias for food cues. The mediation analyses showed that attentional bias mediated the relationship between reward sensitivity and food craving. Those findings suggest that the association between individual differences in reward sensitivity and food craving may be attributed to attentional bias for food-related cues.