Research Area: Body Weight/Satiety

Zelicha, H., D. Schwarzfuchs, I. Shelef, Y. Gepner, G. Tsaban, L. Ten, A.Y. Meir, A. Bilitzky, O. Komy, N. Cohen, N. Bril, M. Rein, D. Serfaty, S. Kenigsbuch, Y. Chassidim, B. Sarusi, J. Thiery, U. Ceglarek, M. Stumvoll, M. Blüher, Y.S. Haviv, M.J. Stampfer, A. Rudich, I. Shai, 2017. Changes of renal sinus fat and renal parenchymal fat during an 18-month randomized weight loss trial. Clin Nutr. http://dx.doi.org/10.1016/j.clnu.2017.04.007.

Background & Aims: Data regarding the role of kidney adiposity, its clinical implications, and its dynamics during weight-loss are sparse. We investigated the effect of long-term weight-loss induced intervention diets on dynamics of renal-sinus-fat, an ectopic fat depot, and %renal-parenchymal-fat, lipid accumulation within the renal parenchyma. Methods: We randomized 278 participants with abdominal obesity/dyslipidemia to low-fat or Mediterranean/low-carbohydrate diets, with or without exercise. We quantified renal-sinus-fat and %renal-parenchymal-fat by whole body magnetic-resonance-imaging. Results: Participants (age = 48 years; 89% men; body-mass-index = 31 kg/m²) had 86% retention to the trial after 18 months. Both increased renal-sinus-fat and %renal-parenchymal-fat were directly associated with hypertension, and with higher abdominal deep-subcutaneous-adipose-tissue and visceral-adipose-tissue (p of trend < 0.05 for all) after adjustment for body weight. Higher renal-sinus-fat was associated with lower estimated-glomerular-filtration-rate and with higher microalbuminuria and %HbA1C beyond body weight. After 18 months of intervention, overall renal-sinus-fat (-9%; p < 0.05 vs. baseline) but not %renal-parenchymal-fat (-1.7%; p = 0.13 vs. baseline) significantly decreased, and similarly across the intervention groups. Renal-sinus-fat and %renal-parenchymal-fat changes were correlated with weight-loss per-se (p < 0.05). In a model adjusted for age, sex, and visceral-adipose-tissue changes, 18 months reduction in renal-sinus-fat associated with decreased pancreatic, hepatic and cardiac fats (p < 0.05 for all) and with decreased cholesterol/high-density lipoprotein-cholesterol (HDL-c) (β = 0.13; p = 0.05), triglycerides/HDL-c (β = 0.13; p = 0.05), insulin (β = 0.12; p = 0.05) and gamma glutamyl transpeptidase (β = 0.24; p = 0.001), but not with improved renal function parameters or blood pressure. Decreased intake of sodium was associated with a reduction in %renal-parenchymal-fat, after adjustment for 18 months weight-loss (β = 0.15; p = 0.026) and hypertension (β = 0.14; p = 0.04). Conclusions: Renal-sinus-fat and renal-parenchymal-fat are fairly related to weight-loss. Decreased renal-sinus-fat is associated with improved hepatic parameters, independent of changes in weight or hepatic fat, rather than with improved renal function or blood pressure parameters.

Wibisono,^{C., Y. Probst, E. Neale, L. Tapsell, 2017. Changes in diet quality during a 12 month weight loss randomised controlled trial. BMC Nutrition. 3:38 Doi: 10.1186/s40795-017-0157-z.}

Abstract: Background: Reductions in energy intake are seen in weight loss trials, but whether this occurs with improvements to diet quality (DQ) is less established. The aim of this study was to evaluate changes in diet quality in a sample of volunteers in a weight loss trial. Methods This was a secondary analysis of dietary data from a lifestyle intervention trial (the HealthTrack study) which advised on dietary guidelines. The trial ran for 12 months with three treatment groups: control (general advice C), intervention (individualised advice, I), and intervention plus a supplement of walnuts (IW). Both the published a priori diet quality score (APDQS, maximum score 164) and a study specific Diet Quality Tracker (DQT, maximum score 44) indicated compliance to dietary advice. DQ scores calculated at 0, 3months and 12months were evaluated using two-way RMANOVA, one-way ANOVA and one-way RMANOVA. Changes in intakes of food groups and nutrients were analysed using Kruskal-Wallis and Friedman’s tests. Results There were no differences between groups at baseline, but at 3months IW recorded higher DQ scores (APDQS:96 ± 10; DQT:22 ± 5, P < 1 × 10−3 for both) compared to I (APDQS:91 ± 13, P < 1 × 10−3; DQT:21 ± 4, P < 1 × 10−2) and C (APDQS:87 ± 12, P < 5 × 10−2; DQT:19 ± 4, P > 5 × 10−2), and a higher consumption of nuts at 3 months (P < 1 × 10−3), and 12months (P < 1 × 10−2). All groups reported decreased intakes of discretionary foods/beverages assessed by the DQT (P < 1 × 10−3 for IW and I; P < 1 × 10−2 for C). The APDQS showed this as reduced intakes of grain-based desserts (P < 1 × 10−3 at 3 and 12months), and salty snacks at 12months (P < 1 × 10−3 for IW and I; P < 5 × 10−2 for C). Intakes of monounsaturated and saturated fatty acids were lowest, and polyunsaturated fatty acids highest for IW (P < 1 × 10−3), resulting in a higher dietary polyunsaturated:saturated fat ratio (P < 1 × 10−3). Conclusions: Lifestyle intervention addressing dietary guidelines can lead to significant reductions in consumption of discretionary foods and saturated fat, but individualised advice may have a greater impact on improving overall DQ regardless of DQI used. Providing a healthy food supplement may help assure higher DQ and where the food is walnuts, produce commensurate differences in dietary fatty acid profiles.

Tapsell, L.C., M. Lonergan, M.J. Batterham, E.P. Neale, A. Martin, R. Thorne, F. Deane, G. Peoples, 2017. Effect of interdisciplinary care on weight loss: a randomized controlled trial. BMJ Open. 7:e014533. doi:10.1136/ bmjopen-2016-014533.

Objective: To determine the effectiveness of a novel interdisciplinary treatment compared with usual care on weight loss in overweight and obese adult volunteers. Design Single blinded controlled trial. Participants randomly assigned to usual care (C, general guideline based diet and exercise advice), intervention (I, interdisciplinary protocol) or intervention + a healthy food supplement (30 g walnuts/day) (IW). Setting Community based study, Illawarra region, south of Sydney, Australia. Participants: Generally well volunteer adult residents, 25-54 years, body mass index (BMI) 25-40kg/m2 were eligible. At baseline 439 were assessed, 377 were randomised, 298 completed the 3-month intensive phase and 178 completed the 12-month follow-up. Interventions Treatment was provided at clinic visits intensively (0 months, 1 month, 2 months, 3 months) then quarterly to 12 months. Support phone calls were quarterly. All participants underwent blinded assessments for diet, exercise and psychological status. Primary and secondary measures: The primary outcome was difference in weight loss between baseline and 12 months (clinically relevant target 5% loss). Secondary outcomes were changes in blood pressure, fasting blood glucose and lipids, and changes in diet, exercise and psychological parameters. Results At 12 months, differences in weight loss were identified (p<0.001). The I group lost more than controls at 3 months (91.11 (92.23,90.00), p<0.05) and the IW more than controls at 3 months (91.25 (92.35,90.15), p<0.05) and 6 months (92.20 (93.90,90.49), p<0.01). The proportion achieving 5% weight loss was significantly different at 3 months, 6 months and months (p=0.04, p=0.03, p=0.03), due to fewer controls on target at 3 months, 6 months and 9 months and more IW participants at 6 months. Reductions in secondary outcomes (systolic blood pressure, blood glucose/lipid parameters and lifestyle measures) followed the pattern of weight loss. Conclusions An interdisciplinary intervention produced greater and more clinically significant and sustained weight loss compared with usual care. The intensive phase was sufficient to reach clinically relevant targets, but long-term management plans may be required.

Stevenson, J.L., C.M. Paton, J.A. Cooper, 2017. Hunger and satiety responses to high-fat meals after a high-polyunsaturated fat diet: A randomized trial. Nutrition. 41:1-10.

Objective Previous studies have shown that polyunsaturated fats (PUFAs) elicit a greater response in satiety after a single-meal challenge compared with other types of fats. The long-term effects of PUFAs on satiety, however, remain unknown. The aim of this study was to determine subjective and physiological hunger and satiety responses to high-fat (HF) meals before and after a 7-d PUFA-rich diet. Methods Twenty-six, healthy weight (body mass index 18–24.9 kg/m2), sedentary adults were randomly assigned to either a 7-d PUFA-rich diet (n = 8 men and n = 8 women) or a 7-d control diet (n = 5 men and n = 5 women). After a 3-d lead-in diet, participants reported for the baseline visit where anthropometrics, fasting visual analog scale (VAS) measurements, and a fasting blood sample were collected. Then, two HF meals (breakfast and lunch) were consumed. Postprandial blood draws and VAS measures were collected approximately every 30 min for 4 h after each meal, for a total of 8 h. Results From pre- to post-PUFA–rich diet, there was a decrease in fasting ghrelin (P < 0.05) and an increase in fasting peptide YY (PYY; P < 0.05); however, there were no changes in fasting insulin or leptin concentrations. The postprandial response for PYY was higher after the PUFA-rich diet visit compared to baseline (P < 0.01). However, there were no differences in the postprandial response for ghrelin, insulin, leptin, or VAS measures from pre- to post-diet in either the PUFA-rich diet or control (ns). Conclusion A PUFA-rich diet consumed for 7 d favorably altered fasting and postprandial physiological markers of hunger and satiety; yet, did not alter subjective ratings of hunger or fullness.

Rock, C.L., S.W. Flatt, H.S. Barkai, B. Pakiz, D.D. Heath, 2017. A walnut-containing meal had similar effects on early satiety, CCK, and PYY, but attenuated the postprandial GLP-1 and insulin response compared to a nut-free control meal. Appetite. 117:51-57.

Regular nut consumption is associated with lower adiposity and reduced weight gain in adulthood. Walnut feeding studies have observed minimal effect on body weight despite potential additional energy intake. Several mechanisms may explain why consuming nuts promotes weight control, including increased early phase satiety, possibly reflected in postprandial response of gastrointestinal and pancreatic peptides hypothesized to affect appetite. The purpose of this study was to compare postprandial insulin, glucagon and gastrointestinal peptide response and satiety following a meal with ∼54% of energy from walnuts or cream cheese, using a within-subject crossover study design in overweight/obese adults (N = 28). Sixty minutes after the walnut-containing meal, glucagon-like peptide-1 was lower than after the reference meal (p=0.0433), and peptide YY, cholecystokinin and ghrelin did not differ after the two meals. Sixty and 120 min after the walnut-containing meal, pancreatic polypeptide (p = 0.0014 and p = 0.0002) and glucose-dependent insulinotropic peptide (p < 0.0001 and p = 0.0079) were lower than after the reference meal, and 120 min after the walnut-containing meal, glucagon was higher (p=0.0069). Insulin and C-peptide increased at 60 min in response to both meals but were lower at 120 min after the walnut-containing meal (p=0.0349 and 0.0237, respectively). Satiety measures were similar after both meals. These findings fail to support the hypothesis that acute postprandial gastrointestinal peptide response to a walnut-containing meal contributes to increased satiety. However, inclusion of walnuts attenuated the postprandial insulin response, which may contribute to the more favorable lipid profile observed in association with regular walnut consumption.

Farr, O.M., D. Tuccinardi, J. Upadhyay, S.M. Oussaada, C.S. Mantzoros, 2017. Walnut consumption increases activation of the insula to highly desirable food cues: A randomized, double-blind, placebo-controlled, cross-over fMRI study. Diabetes Obes Metab. 2017 Jul 17. doi: 10.1111/dom.13060. [Epub ahead of print]

Aims: The use of walnuts is recommended for obesity and type 2 diabetes, although the mechanisms through which walnuts may improve appetite and/or glycemic control remain largely unknown. Materials and Methods: To determine whether short-term walnut consumption could alter the neural control of appetite using functional magnetic resonance imaging, we performed a randomized, placebo-controlled, double-blind, cross-over trial of 10 patients who received, while living in the controlled environment of a clinical research center, either walnuts or placebo (using a validated smoothie delivery system) for 5 days each, separated by a wash-out period of one month. Results: Walnut consumption decreased feelings of hunger and appetite assessed using visual analog scales and increased the activation of the right insula to highly desirable food cues. Conclusions: These findings suggest that walnut consumption may increase salience and cognitive control processing of highly desirable food cues, leading to the beneficial metabolic effects observed.