Dietary Intervention Period Research Articles

Colorectal Carcinogenesis in the A/J Min/+ Mouse Model is Inhibited by Hemin, Independently of Dietary Fat Content and Fecal Lipid Peroxidation Rate

BackgroundIntake of red meat is considered a risk factor for colorectal cancer (CRC) development, and heme, the prosthetic group of myoglobin, has been suggested as a potential cause. One of the proposed molecular mechanisms of heme-induced CRC is based on an increase in the rate of lipid peroxidation catalysed by heme.MethodsIn the present work, the novel A/J Min/+ mouse model for Apc-driven colorectal cancer was used to investigate the effect of dietary heme (0.5 μmol/g), combined with high (40 energy %) or low (10 energy %) dietary fat levels, on intestinal carcinogenesis. At the end of the dietary intervention period (week 3–11), spontaneously developed lesions in the colon (flat aberrant crypt foci (flat ACF) and tumors) and small intestine (tumors) were scored and thiobarbituric reactive substances (TBARS), a biomarker for lipid peroxidation was analysed in feces.ResultsDietary hemin significantly reduced colonic carcinogenesis. The inhibitory effect of hemin was not dependent on the dietary fat level, and no association could be established between colonic carcinogenesis and the lipid oxidation rate measured as fecal TBARS. Small intestinal carcinogenesis was not affected by hemin. Fat tended to stimulate intestinal carcinogenesis.ConclusionsContradicting the hypothesis, dietary hemin did inhibit colonic carcinogenesis in the present study. The results indicate that fecal TBARS concentration is not directly related to intestinal lesions and is therefore not a suitable biomarker for CRC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2874-0) contains supplementary material, which is available to authorized users.

Estimating real cell size distribution from cross-section microscopy imaging.

Microscopy imaging is an essential tool for medical diagnosis and molecular biology. It is particularly useful for extracting information about disease states, tissue heterogeneity and cell specific parameters such as cell type or cell size from biological specimens. However, the information obtained from the images is likely to be subjected to sampling and observational bias with respect to the underlying cell size/type distributions. We present an algorithm, Estimate Tissue Cell Size/Type Distribution (EstiTiCS), for the adjustment of the underestimation of the number of small cells and the size of measured cells while accounting for the section thickness independent of the tissue type. We introduce the sources of bias under different tissue distributions and their effect on the measured values with simulation experiments. Furthermore, we demonstrate our method on histological sections of paraffin-embedded adipose tissue sample images from 57 people from a dietary intervention study. This data consists of measured cell size and its distribution over the dietary intervention period at four time points. Adjusting for the bias with EstiTiCS results in a closer fit to the true/expected adipocyte size distribution with earlier studies. Therefore, we conclude that our method is suitable as the final step in estimating the tissue wide cell type/size distribution from microscopy imaging pipeline. Source code and its documentation are available at https://github.com/michaelLenz/EstiTiCS The whole pipeline of our method is implemented in R and makes use of the 'nloptr' package. Adipose tissue data used for this study are available on request. Michael.Lenz@Maastrichtuniversity.nl, Gokhan.Ertaylan@Maastrichtuniversity.nl.

Abstract CT043: Low-fat dietary pattern and breast cancer mortality in the Women's Health Initiative (WHI) randomized trial

Abstract Context: The Women's Health Initiative Dietary Modification trial randomized 48,835 postmenopausal women at 40 US clinical centers from 1993 to 1998. With 1,767 incident breast cancers, during 8.3 years (mean) dietary intervention, there were fewer breast cancers in the dietary group (HR 0.92 95% CI 0.84-1.01, P = 0.09) with somewhat fewer deaths from breast cancer (HR 0.77 95% CI 0.48-1.22), but no apparent post-intervention influence (JAMA 2006; 295:629; Cancer Epi Bio Prev 2014; 23:2924). These findings suggested dietary intervention may reduce breast cancers associated with greater mortality. New information on breast cancer mortality is analyzed here. Objective: To examine low-fat dietary pattern influence on breast cancer mortality for cases diagnosed during the dietary intervention period. Design and Setting: Secondary analyses from a randomized controlled dietary modification trial. Participants: 48,835 postmenopausal women, 50 to 79 years old, with no previous breast or colorectal cancer, with dietary fat intake greater than 32% of total energy and with a mammogram not suspicious for cancer at entry. Interventions: Dietary group (40%, n = 19,541) which included nutritionist led group sessions throughout the 8.3 year (mean) dietary intervention. Usual diet control group participants received diet-related education materials (60%, n = 29,294). Main Outcome Measures: Deaths from breast cancer (breast cancer followed by deaths directly attributed to the cancer) and deaths after breast cancer (breast cancer followed by death from any cause) during 8.3 years (mean) dietary intervention including all 48,835 study participants measured from randomization. Secondarily, breast cancer overall survival (survival from diagnosis with death from any cause) for the 1767 breast cancer cases identified during the dietary intervention period and followed through August, 2014. Results: Baseline demographic characteristics and breast cancer risk factors were closely comparable in the two randomization groups as was screening mammography frequency throughout. In the dietary group, fat intake decreased, vegetable, fruit and grain consumption increased and body weight was modestly reduced (all P <0.001). In the dietary group, deaths from breast cancer were somewhat lower (HR 0.68 95% CI 0.43-1.07, P = 0.09), while deaths after breast cancer were significantly reduced (40 vs 94 cases; HR 0.65 95% CI 0.45-0.94, P = 0.02). Breast cancer overall survival, among the 1,767 breast cancer cases, after 10.9 years (mean) post-diagnosis follow-up, was greater in the dietary group (10 year survival, 82% vs 78%, HR 0.80 95% CI 0.66-0.97, P = 0.02). Temporal trends for dietary modification influence on breast cancer overall survival identified more favorable effect during dietary intervention then post-intervention (interaction P = 0.02). Causes of death (available for 400 of 487 breast cancer cases) included breast cancer (41%, 165 deaths), other cancer (17%, 67 deaths), and cardiovascular disease (16%, 64 deaths, HR 0.45 95% CI 0.25-0.81 for dietary influence). Conclusion: Compared to a usual diet control group, a low-fat dietary pattern led to a lower incidence of deaths after breast cancer. This reduction is due, in part, to better survival following breast cancer diagnosis. Citation Format: Rowan T. Chlebowski, Aaron K. Aragaki, Garnet L. Anderson, Cynthia A. Thomson, Joanne E. Manson, Michael S. Simon, Barbara V. Howard, Thomas E. Rohan, Linda Snetselaar, Dorothy Lane, Wendy E. Barrington, Mara Z. Vitolilns, Catherine Womack, LiHong Qi, Lifang Hou, Fridtjof Thomas, Ross L. Prentice. Low-fat dietary pattern and breast cancer mortality in the Women's Health Initiative (WHI) randomized trial. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT043.

Case Study

Athletes employ various dietary strategies in attempts to attenuate exercise-induced gastrointestinal (GI) symptoms to ensure optimal performance. PURPOSE: This case-study outlines a novel GI-targeted approaches via the implementation of a short-term low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) diet, with the aim to attenuate persistent running-specific GI symptoms in a competitive multisport athlete (male, 86kg, 57.9 ml.kg.min-1 V02max, 10-15 hrs.week-1 training, with no diagnosed GI disorder). METHODS: Using a single blinded approach, a habitual diet was compared to a 6-day low FODMAP intervention diet (81 ± 5g vs 7.2 ± 5.7g FODMAPs.day-1) for their effect on GI symptoms and perceptual wellbeing. Training was similar during the habitual and dietary intervention period. Daily GI symptom ratings were recorded after exercise (During) and at the end of the day (Daily) as well as the Daily Analysis of Life Demands for Athletes (DALDA). RESULTS:Daily and During GI symptom scores (scale 0-9) ranged from 0-4 in level of severity during the habitual dietary period while during the low FODMAP dietary period all scores were 0 (no symptoms at all). DALDA scores for ‘worse than normal’ ranged from 3-10 vs 0-8 in the habitual and low FODMAP dietary periods, respectively, indicating improvement. CONCLUSION: This intervention was effective for this GI symptom prone athlete; however, appropriately designed large sample research is required to assess the suitability of low FODMAP diets for reducing GI distress in other symptomatic athletes.

A 3-day high-fat/low-carbohydrate diet does not alter exercise-induced growth hormone response in healthy males

ObjectiveThe purpose of the present study was to examine the effects of 3days isoenergetic high-fat/low-carbohydrate diet (HF-LC) relative to low-fat/high-carbohydrate diet (LF-HC) on the exercise-induced growth hormone (GH) response in healthy male subjects. DesignTen healthy young males participated in this study. Each subject consumed the HF-LC (18±1% protein, 61±2% fat, 21±1% carbohydrate, 2720kcal per day) for 3 consecutive days after consuming the LF-HC (18±1% protein, 20±1% fat, 62±1% carbohydrate, 2755kcal per day) for 3 consecutive days. After each dietary intervention period, the hormonal and metabolic responses to an acute exercise (30min of continuous pedaling at 60% of V˙O2max) were compared. The intramyocellular lipid (IMCL) contents in the vastus lateralis, soleus, and tibialis anterior were evaluated by proton magnetic resonance spectroscopy. ResultsSerum GH concentrations increased significantly during the exercise after both the HF-LC and LF-HC periods (P<0.05). However, the exercise-induced GH response was not significantly different between the two periods. Fat utilization and lipolytic responses during the exercise were enhanced significantly after the HF-LC period compared with the LF-HC period. IMCL content did not differ significantly in any portion of muscle after the dietary interventions. ConclusionsWe could not show that short-term HF-LC consumption changed significantly exercise-induced GH response or IMCL content in healthy young males.

Aggregate blood pressure responses to serial dietary sodium and potassium intervention: defining responses using independent component analysis.

BackgroundHypertension is a complex trait that often co-occurs with other conditions such as obesity and is affected by genetic and environmental factors. Aggregate indices such as principal components among these variables and their responses to environmental interventions may represent novel information that is potentially useful for genetic studies.ResultsIn this study of families participating in the Genetic Epidemiology Network of Salt Sensitivity (GenSalt) Study, blood pressure (BP) responses to dietary sodium interventions are explored. Independent component analysis (ICA) was applied to 20 variables indexing obesity and BP measured at baseline and during low sodium, high sodium and high sodium plus potassium dietary intervention periods. A “heat map” protocol that classifies subjects based on risk for hypertension is used to interpret the extracted components. ICA and heat map suggest four components best describe the data: (1) systolic hypertension, (2) general hypertension, (3) response to sodium intervention and (4) obesity. The largest heritabilities are for the systolic (64 %) and general hypertension (56 %) components. There is a pattern of higher heritability for the component response to intervention (40–42 %) as compared to those for the traditional intervention responses computed as delta scores (24 %–40 %).ConclusionsIn summary, the present study provides intermediate phenotypes that are heritable. Using these derived components may prove useful in gene discovery applications.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-015-0226-8) contains supplementary material, which is available to authorized users.

The Role of Low FODMAP Diet in the Management of Irritable Bowel Syndrome

The Role of Low FODMAP Diet in the Management of Irritable Bowel Syndrome

Reduced anxiety in forensic inpatients after a long-term intervention with Atlantic salmon.

The aim of the present study was to investigate the effects of Atlantic salmon consumption on underlying biological mechanisms associated with anxiety such as heart rate variability (HRV) and heart rate (HR) as well as a measure of self-reported anxiety. Moreover, these biological and self-reported outcome measures were investigated in relation to specific nutrients; vitamin D status, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Ninety-five male forensic inpatients were randomly assigned into a Fish (Atlantic salmon three times per week from September to February) or a Control group (alternative meal, e.g., chicken, pork, or beef three times per week during the same period). HRV measured as the root mean square of successive differences (rMSSD), HR, state- and trait-anxiety (STAI), were assessed before (pre-test) and at the end of the 23 weeks dietary intervention period (post-test). The Fish group showed significant improvements in both rMSSD and HR. The Fish group also showed significant decreases in state-anxiety. Finally, there was a positive relationship between rMSSD and vitamin D status. The findings suggest that Atlantic salmon consumption may have an impact on mental health related variables such as underlying mechanisms playing a key role in emotion-regulation and state-anxiety.

Effect of salt intake and potassium supplementation on serum renalase levels in Chinese adults: a randomized trial.

Renalase, a recently discovered enzyme released by the kidneys, breaks down blood-borne catecholamines and may thus regulate blood pressure (BP). Animal studies have suggested that high levels of dietary salt might reduce blood and kidney renalase levels. We conducted a randomized trial to assess the effects of altered salt and potassium intake on serum renalase levels and the relationship between serum renalase levels and BP in humans.Forty-two subjects (28–65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day of NaCl), a high-salt diet for additional 7 days (18.0 g/day of NaCl), and a high-salt diet with potassium supplementation for final 7 days (18.0 g/day of NaCl + 4.5 g/day of KCl).Serum renalase levels were significantly higher than baseline levels during the low-salt diet intervention period. Renalase levels decreased with the change from the low-salt to high-salt diet, whereas dietary potassium prevented the decrease in serum renalase induced by the high-salt diet. There was a significant inverse correlation between the serum renalase level and 24-h urinary sodium excretion. No significant correlation was found between the renalase level and BP among the different dietary interventions.The present study indicates that variations in dietary salt intake and potassium supplementation affect the serum renalase concentration in Chinese subjects.

New insights from a β-glucan human intervention study using NMR metabolomics

This study investigates the plasma metabolic effectiveness from 3.3g mixed linkage barley or oat β-glucan fibre per day by 1H NMR spectroscopy on plasma samples and multivariate data analysis. Three large-scale extracted, equally sized but structurally different β-glucans were tested in a blinded randomised cross-over design using young healthy adults, where the β-glucans were compared to a non-fibre control during a 21day dietary intervention period. Subject variance was found to dominate the metabolomics data although the variations in subject age and BMI were very small. The second most influential variation was found to be due to gender as characteristic lipoprotein profiles were found for male and female samples. The 3.3g/day did not perturb the blood homeostasis in healthy adults as no systematic differences between 3-week β-glucan treatments and control were found. The present study constitutes the first metabolomic β-glucan human intervention study which proves complementary and confirmatory with respect to previous nutritional investigations evaluating traditional cardiovascular disease risk markers.

Two Randomized Cross-Over Trials Assessing the Impact of Dietary Gluten or Wholegrain on the Gut Microbiome and Host Metabolic Health

Background: Gut microbiota composition and activity may be changed by dietary factors and possibly affect metabolic health. Dietary gluten and wholegrain are suggested to influence metabolism in a negative and positive direction, respectively. Objective: Describe the design and rational as well as baseline characteristics of two human intervention studies, within the Gut, Grain and Greens (3G) Center, investigating the effects of a gluten-poor and wholegrain-rich diet on microbiota composition and metabolic health. Design: The gluten and wholegrain studies had a randomized, controlled, cross-over design each comprising two eight-week dietary intervention periods, separated by a six-week wash-out period. Each trial included 60 men and women exhibiting an increased metabolic risk. In the gluten study a gluten-poor diet was compared with a gluten-rich dietary fiber-controlled diet, and in the wholegrain study a wholegrain-rich diet was compared with a refined grain diet. The control diet was identical in both studies, being concomitantly high in gluten and refined. Participants substituted all cereal products with provided intervention products which they consumed ad libitum. Before and after each intervention period, fecal samples for quantitative metagenomic analyses were collected and an examination day was conducted. The primary outcome of the gluten intervention study was changes in the gut microbiota composition, while insulin sensitivity was an additional primary outcome of the wholegrain study. Further, a number of secondary outcomes were investigated. Results: 52 and 50 participants completed the gluten and wholegrain intervention study, respectively. Participants had slightly elevated fasting glucose levels and increased waist circumference. Biological outcomes of the two studies will be published elsewhere. Conclusion: The studies have the potential to provide new insights into the interplay of gut microbiota and metabolic health in individuals with increased risk of developing metabolic disorders.

Glucose uptake by the brain on chronic high-protein weight-loss diets with either moderate or low amounts of carbohydrate

Previous work has shown that hunger and food intake are lower in individuals on high-protein (HP) diets when combined with low carbohydrate (LC) intakes rather than with moderate carbohydrate (MC) intakes and where a more ketogenic state occurs. The aim of the present study was to investigate whether the difference between HPLC and HPMC diets was associated with changes in glucose and ketone body metabolism, particularly within key areas of the brain involved in appetite control. A total of twelve men, mean BMI 34·9 kg/m², took part in a randomised cross-over trial, with two 4-week periods when isoenergetic fixed-intake diets (8·3 MJ/d) were given, with 30% of the energy being given as protein and either (1) a very LC (22 g/d; HPLC) or (2) a MC (182 g/d; HPMC) intake. An ¹⁸fluoro-deoxyglucose positron emission tomography scan of the brain was conducted at the end of each dietary intervention period, following an overnight fast (n 4) or 4 h after consumption of a test meal (n 8). On the next day, whole-body ketone and glucose metabolism was quantified using [1,2,3,4-¹³C]acetoacetate, [2,4-¹³C]3-hydroxybutyrate and [6,6-²H₂]glucose. The composite hunger score was 14% lower (P= 0·013) for the HPLC dietary intervention than for the HPMC diet. Whole-body ketone flux was approximately 4-fold greater for the HPLC dietary intervention than for the HPMC diet (P< 0·001). The 9-fold difference in carbohydrate intakes between the HPLC and HPMC dietary interventions led to a 5% lower supply of glucose to the brain. Despite this, the uptake of glucose by the fifty-four regions of the brain analysed remained similar for the two dietary interventions. In conclusion, differences in the composite hunger score observed for the two dietary interventions are not associated with the use of alternative fuels by the brain.

Adipose triglyceride lipase and hormone-sensitive lipase protein expression in subcutaneous adipose tissue is decreased after an isoenergetic low-fat high-complex carbohydrate diet in the metabolic syndrome

The objective was to determine the contribution of dietary fat quantity and composition to lipolysis and lipolytic gene expression in humans in relation to obesity, insulin resistance, and the metabolic syndrome (MetS). Men and women with the MetS were randomly assigned to one of four isoenergetic diets: a high-fat saturated fat diet (n=10), a high-fat monounsaturated fat diet (n=7), and two low-fat high-complex carbohydrate (LFHCC) diets, one supplemented with 1.24g/day long-chain n-3 PUFA (LFHCC: n=7, LFHCCn-3: n=8). Subcutaneous adipose tissue biopsies were taken before and after the 12-week dietary intervention period. ATGL and HSL mRNA and protein expression was determined. Whole body rate of appearance of free fatty acids (RaFFA) was determined by intravenous infusion of [2H2]-palmitate in a subgroup of men (n=20). Adipose tissue ATGL and HSL mRNA and protein expression was not affected by alterations in dietary fat composition. Pooled analysis comparing the low- and high-fat diets showed that ATGL and HSL protein expression was significantly reduced after the LFHCC diets (P=.04), irrespective of long-chain n-3 PUFA. Moreover, LFHCC diets lowered fasting insulin, HOMAIR, and (LDL)-cholesterol concentrations (P≤.05). Changes in ATGL and HSL protein expression was positively associated with changes in whole body RaFFA (P<.03). The low-fat high-complex carbohydrate diets reduced ATGL and HSL protein expression and significantly improved circulating lipids and insulin sensitivity. Under isoenergetic conditions, dietary fat quantity, rather than composition, may be most important for modulating subcutaneous adipose tissue ATGL and HSL protein expression.

Dietary fish oil alters the lysophospholipid metabolomic profile and decreases urinary 11-dehydro thromboxane B 2 concentration in healthy Beagles

Increased concentrations of dietary fish oil and antioxidants have been shown previously to change circulating concentrations of individual fatty acids (FAs) and vitamin E. The purpose of this study was to further investigate the effects of vitamins E and C, in combination with dietary fish oil, on selected blood and urinary biomarkers. Fifty adult Beagle dogs (mean age 5.3 years, range 1.4–14.2 years) were randomized into five dietary treatment groups for 90 days. All foods were complete and balanced and met the nutrient profiles of AAFCO for adult dogs. For 60 days before study initiation, dogs consumed a pretrial food that contained 74 IU/kg vitamin E and 0 mg/kg vitamin C. The five experimental foods were confirmed by analytical methods to contain ≥640 IU/kg vitamin E and 130 mg/kg vitamin C (as fed). Experimental foods ranged from low levels of EPA and DHA (pretrial food and lowest experimental food had 0.01% EPA and no detectable DHA) to the highest experimental food with 0.25% EPA and 0.17% DHA. Serum was analyzed for FAs, vitamin E, and cholesterol concentrations; urine was analyzed for 11-dehydro thromboxane B 2 (TXB 2). Serum was also used for metabolomic analysis. FA intake ranged from 0.02 g/day EPA and 0.02 g/day DHA to 0.58 g/day EPA and 0.39 g/day DHA. Increasing dietary concentrations of EPA and DHA resulted in increased serum concentrations of EPA and DHA in a dose-dependent fashion. Greater dietary vitamin E intake resulted in increased serum vitamin E concentrations ( P < 0.01). Higher serum cholesterol was also associated with higher serum vitamin E concentrations ( P < 0.01). In turn, changes in serum cholesterol concentration were associated with diet-induced changes in serum FA concentrations (all P < 0.01). At the beginning of the dietary treatment period the most significant predictor of urine 11-dehydro TXB 2 concentration was age, followed by lean-body mass. After dietary treatment with different amounts of fish oil, age (increases 11-dehydro TXB 2) was followed by EPA concentration as a significant negative predictor of urine 11-dehydro TXB 2 concentration (increasing serum concentrations of EPA decrease 11-dehydro TXB 2), and then lean-body mass (decreases 11-dehydro TXB 2). Serum docosahexaenoyl-glycerophosphocholine concentration was increased by feeding fish oil in a dose–response manner. In summary, serum vitamin E concentration is enhanced primarily by feeding vitamin E and secondarily by serum cholesterol concentration. When feeding diets enriched with fish oil, the major negative predictor of urinary 11-dehydro TXB 2 concentration is serum EPA concentration. Plasma lysophospholipids can be dynamically regulated by dietary fish oil supplementation.

Effect of water content in a canned food on voluntary food intake and body weight in cats

To determine whether water content in a canned food diet induces decreases in voluntary energy intake (EI) or body weight (BW) in cats fed ad libitum. 16 sexually intact male domestic shorthair cats. Maintenance EI was determined for 2 months in 10 weight-stable cats consuming a control diet (typical colony diet). Cats were allocated into 2 groups of equal BW and fed a canned diet (with-water [WW] diet) or a freeze-dried version of the canned diet (low-water [LW] diet) twice daily. Diets were identical in nutrient profile on a dry-matter basis. Each dietary treatment period of the crossover experiment lasted 3 weeks, with a 3-week washout period between diets. Body composition measurements were determined by use of deuterium oxide at the end of each dietary treatment. Daily food intake was measured for determination of dry-matter intake and EI. Six other cats were used in preference tests for the 3 diets. EI was significantly decreased for the WW diet (mean ± SD, 1,053.0 ± 274.9 kJ/d), compared with EI for the LW diet (1,413.8 ± 345.8 kJ/d). Cats had a significant decrease in BW during consumption of the WW diet. Body composition was unaltered by diet. In short-term preference tests, cats ate significantly more of the WW than the LW diet. Bulk water in the WW diet stimulated decreases in EI and BW in cats. The impact of water content on energy density and food consumption may help promote weight loss in cats.

Blood profiling of proteins and steroids during weight maintenance with manipulation of dietary protein level and glycaemic index

Weight regain after weight loss is common. In the Diogenes dietary intervention study, a high-protein and low-glycaemic index (GI) diet improved weight maintenance. The objective of the present study was to identify (1) blood profiles associated with continued weight loss and weight regain (2) blood biomarkers of dietary protein and GI levels during the weight-maintenance phase. Blood samples were collected at baseline, after 8 weeks of low-energy diet-induced weight loss and after a 6-month dietary intervention period from female continued weight losers (n 48) and weight regainers (n 48), evenly selected from four dietary groups that varied in protein and GI levels. The blood concentrations of twenty-nine proteins and three steroid hormones were measured. The changes in analytes during weight maintenance largely correlated negatively with the changes during weight loss, with some differences between continued weight losers and weight regainers. Increases in leptin (LEP) and C-reactive protein (CRP) were significantly associated with weight regain (P<0·001 and P=0·005, respectively), and these relationships were influenced by the diet. Consuming a high-protein and high-GI diet dissociated the positive relationship between the change in LEP concentration and weight regain. CRP increased during the weight-maintenance period only in weight regainers with a high-protein diet (P<0·001). In addition, testosterone, luteinising hormone, angiotensinogen, plasminogen activator inhibitor-1, resistin, retinol-binding protein 4, insulin, glucagon, haptoglobin and growth hormone were also affected by the dietary intervention. The blood profile reflects not only the weight change during the maintenance period, but also the macronutrient composition of the dietary intervention, especially the protein level.

Muscle ceramide content is similar after 3 weeks’ consumption of fat or carbohydrate diet in a crossover design in patients with type 2 diabetes

This study aimed at investigating the effect of prolonged adaptation to fat- or carbohydrate-rich diet on muscle ceramide in type 2 diabetes patients, using a longitudinal crossover study. Eleven type 2 diabetes patients consumed isocaloric fat- or carbohydrate-rich diet for 3 weeks in random order. After each dietary intervention period, muscle glycogen, triacylglycerol and ceramide content and plasma concentrations of insulin, adiponectin, glucose and FFA were determined. Insulin resistance was assessed by HOMA2 calculation. After the dietary period, plasma glucose and insulin, insulin sensitivity, muscle glycogen, triacylglycerol and ceramide content were similar. Plasma adiponectin concentration was significantly higher after fat compared with carbohydrate-rich diet. Results indicated that following fat-rich diet intake muscle ceramide and triacylglycerol concentrations were not different compared with that after carbohydrate-rich diet. Furthermore, plasma adiponectin concentration was higher after fat-rich compared with carbohydrate-rich diet, but insulin sensitivity remained similar despite the major difference in dietary macronutrient composition.

A diet rich in oat bran improves blood lipids and hemostatic factors, and reduces apparent energy digestibility in young healthy volunteers

Oat bran shows cholesterol-lowering properties, but its effects on other cardiovascular risk markers are less frequently investigated. This study examined the effects of oat bran on blood lipids, hemostatic factors and energy utilization. A double-blind, randomized crossover study in 24 adults (age 25.2±2.7 years; body mass index: 24.9±2.9 kg/m2), who completed two 2-week dietary intervention periods: low-fiber diet (control) or an oat bran (control +102 g oat bran/day) diet. Fasting blood samples were drawn before and after each period, and 3-day fecal samples were collected during the last week of each period. Total cholesterol decreased by 14% during the oat bran period compared with 4% during the control period (P<0.001). Non-high-density lipoprotein (HDL) cholesterol decreased by 16% in the oat bran period compared with 3% in the control period (P<0.01), as did total triacylglycerol (21 vs 10%, P<0.05) and very-low-density lipoprotein triacylglycerol 33 vs 9%, P<0.01). Plasminogen activator inhibitor-1 (PAI-1) and factor VII (fVII) levels decreased more during consumption of oat bran compared with the control period (PAI-1: 30 vs 2.3%, P<0.01; fVII: 15 vs 7.6%, <0.001). Fecal volume and dry matter were greater when consuming the oat bran diet compared with the control (P<0.001), and energy excretion was increased by 37% (1014 vs 638 kJ/day, P<0.001); however, changes in body weight did not differ (oat bran:-0.3±0.5 kg; control: 0.0±0.7 kg). Addition of oat bran (6 g soluble fiber/day) to a low-fiber diet lowered total and non-HDL cholesterol, as well as hemostatic factors, and may affect energy balance through reduced energy utilization.

Predictors of weight loss maintenance and attrition during a 6‐month dietary intervention period: results from the DiOGenes study

There is a need to develop tools to predict individual weight loss maintenance and attrition prognosis. We aimed to identify predictors of weight loss maintenance outcome and attrition in subjects from eight European countries in the DiOGenes project. A total of 932 overweight/obese subjects (body mass index: 27-42 kg m(-2) ) were enrolled in an 8-week low-calorie diet (LCD). The 776 subjects (83%) who achieved at least 8% reduction in their initial body weight were randomized into five dietary arms varying in protein content and glycemic index for a 6-month weight maintenance period. Baseline characteristics, weight loss at weeks 1, 3 and 8 of LCD were assessed as predictors of weight loss maintenance and attrition using multivariate regression and correlation models. The multivariate model showed that the 6-month weight loss maintenance was predicted by: 7.889 - 0.343 × weight loss at week 3 + 1.505 × weight loss at week 8 + 2.422 × gender (0 = male and 1 = female gender) (R(2) = 51%, P = 0.0001). A greater weight loss at week 8 was associated with a lower attrition during the subsequent 6-month dietary intervention period (OR = 0.92, 95% CI: 0.88-0.97, P = 0.001). Furthermore, the men showed an increased likelihood for attrition during the dietary intervention period (OR = 1.54, 95% CI: 1.07-2.20, P = 0.02). A greater weight loss during 8 weeks of LCD and female gender predict better 6-month weight maintenance of weight loss, whereas the baseline characteristics did not predict outcome. Attrition could be strongly predicted by gender and weight loss during LCD.

Blood Profile of Proteins and Steroid Hormones Predicts Weight Change after Weight Loss with Interactions of Dietary Protein Level and Glycemic Index

BackgroundWeight regain after weight loss is common. In the Diogenes dietary intervention study, high protein and low glycemic index (GI) diet improved weight maintenance.ObjectiveTo identify blood predictors for weight change after weight loss following the dietary intervention within the Diogenes study.DesignBlood samples were collected at baseline and after 8-week low caloric diet-induced weight loss from 48 women who continued to lose weight and 48 women who regained weight during subsequent 6-month dietary intervention period with 4 diets varying in protein and GI levels. Thirty-one proteins and 3 steroid hormones were measured.ResultsAngiotensin I converting enzyme (ACE) was the most important predictor. Its greater reduction during the 8-week weight loss was related to continued weight loss during the subsequent 6 months, identified by both Logistic Regression and Random Forests analyses. The prediction power of ACE was influenced by immunoproteins, particularly fibrinogen. Leptin, luteinizing hormone and some immunoproteins showed interactions with dietary protein level, while interleukin 8 showed interaction with GI level on the prediction of weight maintenance. A predictor panel of 15 variables enabled an optimal classification by Random Forests with an error rate of 24±1%. A logistic regression model with independent variables from 9 blood analytes had a prediction accuracy of 92%.ConclusionsA selected panel of blood proteins/steroids can predict the weight change after weight loss. ACE may play an important role in weight maintenance. The interactions of blood factors with dietary components are important for personalized dietary advice after weight loss.RegistrationClinicalTrials.gov NCT00390637