1.
Effects of gut microbiota and fatty acid metabolism on dyslipidemia following weight-loss diets in women: Results from a randomized controlled trial.
Ma, Y, Sun, Y, Sun, L, Liu, X, Zeng, R, Lin, X, Li, Y
Clinical nutrition (Edinburgh, Scotland). 2021;(11):5511-5520
Abstract
BACKGROUND & AIMS In our early feeding trial among overweight and obese Chinese women, both low-carbohydrate (LC) and calorie-restricted (CR) diets reduced weight and fat mass, but only the LC diet significantly improved dyslipidemia. We aimed to investigate the impacts of altered gut microbiota, fatty acid (FAs), and acylcarnitines, markers of mitochondrial function on blood lipids. METHODS Fecal and blood samples from 48 participants at baseline and the end of a 12-week trial were used to perform metagenomics and targeted-metabolomics including erythrocyte FAs and plasma acylcarnitines, respectively. RESULTS The two diets altered microbial structure and co-abundance gene clusters (CAGs) at different magnitudes. After a 12-week intervention, the Bacteroidetes/Firmicutes ratio increased significantly in the LC diet (P = 0.015) but not in the CR diet, which only showed an increased trend (P = 0.28). At the microbial function level, the LC group showed lower branched-chain amino acid biosynthesis and higher serine biosynthesis than the CR group. Moreover, the LC diet reduced levels of 14:0 and 16:1n-7 FAs in the de novo lipogenesis pathway, but increased 20:5n-3 compared with the CR diet. Both groups had increased plasma acylcarnitines except that the LC group had larger elevated short-chain acylcarnitines. After backward stepwise selection, a cluster of changed CAGs, FAs and acylcarnitines were found to be associated with improved lipid profile. However, changed CAGs showed higher contribution rates in elevating HDL-cholesterol (81.6%) and reducing triglycerides (89.3%) than changed FAs and acylcarnitines. CONCLUSIONS The two weight-loss diets induced different changes of gut microbiota, plasma acylcarnitines, and erythrocyte FAs. Changes in gut microbiota rather than FA or acylcarnitine profiles showed greater contribution to improved lipid profile in these overweight and obese Chinese women. TRIAL REGISTRATION The trial was registered at http://clinicaltrials.gov/show/NCT01358890.
2.
Substantial Increase in Compliance with Saturated Fatty Acid Intake Recommendations after One Year Following the American Heart Association Diet.
Zhao, M, Chiriboga, D, Olendzki, B, Xie, B, Li, Y, McGonigal, LJ, Maldonado-Contreras, A, Ma, Y
Nutrients. 2018;(10)
Abstract
The American Heart Association (AHA) dietary guidelines recommend 30⁻35% of energy intake (%E) be from total fat, <7%E from saturated fatty acids (SFA), and <1%E from trans fatty acid (TFA). This study evaluates the effect of AHA dietary counselling on fat intake. Between 2009 and 2014, 119 obese adults with metabolic syndrome (MetS), (71% women, average 52.5 years of age, and 34.9 kg/m² of body mass index), received individual and group counselling on the AHA diet, over a one-year study period. Each participant attended 2 individual sessions (months 1 and 12) and 12 group sessions, at one-month intervals. At baseline and one-year, we collected three random 24-h diet recalls (two weekdays and one weekend day). Fat intake patterns over time were analyzed using paired-t test and linear mixed-effect models. There was significant variation on SFA and TFA intake per meal, being highest at dinner, in restaurants, and on weekends. Over the one-year study period, daily intake of total fat, SFA, and TFA decreased by 27%, 37% and 41%, respectively (p-value < 0.01, each). Correspondingly, the percentage of participants complying with AHA's recommendations, increased from 25.2% to 40.2% for total fat (p-value = 0.02); from 2.5% to 20.7% for SFA (p-value < 0.01); and from 45.4% to 62% for TFA (p-value = 0.02). Additionally, SFA intake for all meal types at home decreased significantly (p-value < 0.05, each). AHA dietary counselling significantly increased the compliance with AHA dietary guidelines, with an eightfold increase in compliance in SFA intake. Nonetheless, ~80% of our participants still exceeded the recommended SFA intake. Substantial efforts are needed to encourage low-SFA and low-TFA food preparation at home, with strong public health policies to decrease SFA and TFA in restaurants and prepared foods.
3.
A simple dietary message to improve dietary quality: Results from a pilot investigation.
Olendzki, BC, Ma, Y, Schneider, KL, Merriam, P, Culver, AL, Ockene, IS, Pagoto, S
Nutrition (Burbank, Los Angeles County, Calif.). 2009;(7-8):736-44
Abstract
OBJECTIVE The present study compared the feasibility of two simple messages (a high-fiber diet or a low saturated fat diet) to a combination message (high fiber/low saturated fat) on their potential to affect dietary quality and metabolic health. METHODS Thirty-six subjects were randomized to one of three intervention conditions and received individual dietary counseling sessions. Study assessments occurred at baseline, 3 mo, and 6 mo. RESULTS The sample was 84% female and 94% Caucasian. Mean body mass index was 31kg/m(2). At the 6-mo assessment phase, we retained all 12 patients in the high-fiber diet condition, 10 of 12 in the low saturated fat condition, and 9 of 12 in the combination condition. Participants reported that the dietary fiber intervention was easier to maintain compared with the other two intervention conditions (83% for high dietary fiber versus 60% for low saturated fat versus 33% for the combination, P=0.008). Overall dietary quality improved in all three conditions during the study (P=0.01). In addition to increasing fiber, the high-fiber condition decreased their saturated fat intake, even though a reduction in saturated fat was not a part of that intervention condition. Participants in all three conditions lost an average of 9 lb from baseline weight (P<0.001). CONCLUSION A simple dietary message is feasible and can improve overall dietary quality. Results support the need for a larger randomized controlled trial that is powered to detect the efficacy of a simplified dietary recommendation for dietary quality and metabolic health.