Changes In Carbohydrate Intake Research Articles

Association between changes in carbohydrate intake and long term weight changes: prospective cohort study.

To comprehensively examine the associations between changes in carbohydrate intake and weight change at four year intervals. Prospective cohort study. Nurses' Health Study (1986-2010), Nurses' Health Study II (1991-2015), and Health Professionals Follow-Up Study (1986-2014). 136 432 men and women aged 65 years or younger and free of diabetes, cancer, cardiovascular disease, respiratory disease, neurodegenerative disorders, gastric conditions, chronic kidney disease, and systemic lupus erythematosus before baseline. Weight change within a four year period. The final analyses included 46 722 women in the Nurses' Health Study, 67 186 women in the Nurses' Health Study II, and 22 524 men in the Health Professionals Follow-up Study. On average, participants gained 1.5 kg (5th to 95th centile -6.8 to 10.0) every four years, amounting to 8.8 kg on average over 24 years. Among men and women, increases in glycemic index and glycemic load were positively associated with weight gain. For example, a 100 g/day increase in starch or added sugar was associated with 1.5 kg and 0.9 kg greater weight gain over four years, respectively, whereas a 10 g/day increase in fiber was associated with 0.8 kg less weight gain. Increased carbohydrate intake from whole grains (0.4 kg less weight gain per 100 g/day increase), fruit (1.6 kg less weight gain per 100 g/day increase), and non-starchy vegetables (3.0 kg less weight gain per 100 g/day increase) was inversely associated with weight gain, whereas increased intake from refined grains (0.8 kg more weight gain per 100 g/day increase) and starchy vegetables (peas, corn, and potatoes) (2.6 kg more weight gain per 100 g/day increase) was positively associated with weight gain. In substitution analyses, replacing refined grains, starchy vegetables, and sugar sweetened beverages with equal servings of whole grains, fruit, and non-starchy vegetables was associated with less weight gain. The magnitude of these associations was stronger among participants with overweight or obesity compared with those with normal weight (P<0.001 for interaction). Most of these associations were also stronger among women. The findings of this study highlight the potential importance of carbohydrate quality and source for long term weight management, especially for people with excessive body weight. Limiting added sugar, sugar sweetened beverages, refined grains, and starchy vegetables in favor of whole grains, fruit, and non-starchy vegetables may support efforts to control weight.

Implication of lipid turnover for the control of energy balance.

The ongoing obesity epidemic is a consequence of a progressive energy imbalance. The energy-balance model (EBM) posits that obesity results from an excess in food intake and circulating fuels. A reversal in causality has been proposed recently in the form of the carbohydrate-insulin model (CIM), according to which fat storage drives energy imbalance. Under the CIM, dietary carbohydrates shift energy use in favour of storage in adipose tissue. The dynamics of lipid storage and mobilization could, therefore, be sensitive to changes in carbohydrate intake and represent a measurable component of the CIM. To characterize potential changes in lipid dynamics induced by carbohydrates, mathematical models were used. Here, we propose a coherent mathematical implementation of the CIM-energy deposition model (CIM-EDM), which includes lipid turnover dynamics. Using lipid turnover data previously obtained by radiocarbon dating, we build two cohorts of virtual patients and simulate lipid dynamics during ageing and weight loss. We identify clinically testable lipid dynamic parameters that discriminate between the CIM-EDM and an energy in, energy out implementation of the EBM (EBM-IOM). Using a clinically relevant two-month virtual trial, we additionally identify scenarios and propose mechanisms whereby individuals may respond differently to low-carbohydrate diets. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Different carbohydrate exposures and weight gain—results from a pooled analysis of three population-based studies

BackgroundThe role of carbohydrate quantity and quality in weight gain remains unsolved, and research on carbohydrate subcategories is scarce. We examined total carbohydrates, dietary fiber, total sugar, and sucrose intake in relation to the risk of weight gain in Finnish adults.MethodsOur data comprised 8327 adults aged 25−70 years in three population-based prospective cohorts. Diet was assessed by a validated food frequency questionnaire and nutrient intakes were calculated utilizing the Finnish Food Composition Database. Anthropometric measurements were collected according to standard protocols. Two-staged pooling was applied to derive relative risks across cohorts for weight gain of at least 5% by exposure variable intake quintiles in a 7-year follow-up. Linear trends were examined based on a Wald test.ResultsNo association was observed between intakes of total carbohydrate, dietary fiber, total sugar or sucrose and the risk of weight gain of at least 5%. Yet, total sugar intake had a borderline protective association with the risk of weight gain in participants with obesity (RR 0.63; 95% CI 0.40−1.00 for highest vs. lowest quintile) and sucrose intake in participants with ≥10% decrease in carbohydrate intake during the follow-up (RR 0.78; 95% CI 0.61−1.00) after adjustments for sex, age, baseline weight, education, smoking, physical activity, and energy intake. Further adjustment for fruit consumption strengthened the associations.ConclusionsOur findings do not support an association between carbohydrate intake and weight gain. However, the results suggested that concurrent changes in carbohydrate intake might be an important determinant of weight change and should be further examined in future studies.

Change in carbohydrate intake one year after Roux-en-Y gastric bypass: A prospective study.

Background and objectives: To investigate the effect of carbohydrate intake before laparoscopic Roux-en-Y gastric bypass (LRYGB) on body weight, body composition and glycaemic status after surgery. Methods: In a tertiary centre cohort study, dietary habits, body composition and glycaemic status were evaluated before and 3, 6 and 12 months after LRYGB. Detailed dietary food records were processed by specialized dietitians on the basis of a standard protocol. The study population was subdivided according to relative carbohydrate intake before surgery. Results: Before surgery, 30 patients had a moderate relative carbohydrate intake (26%-45%, M-CHO), a mean body mass index (BMI) of 40.4 ± 3.9 kg/m² and a mean glycated haemoglobin A1c (A1C) of 6.5 ± 1.2% compared to 20 patients with a high relative carbohydrate intake (> 45%, H-CHO), mean BMI of 40.9 ± 3.7 kg/m² (non-significant, NS) and a mean A1C of 6.2% (NS). One year after surgery, body weight, body composition and glycaemic status were similar in the M-CHO (n = 25) and H-CHO groups (n = 16), despite less caloric intake in the H-CHO group (1317 ± 285 g vs. 1646 ± 345 g in M-CHO, p < 0.01). Their relative carbohydrate intake converged to 46% in both groups, but the H-CHO group reduced the absolute total carbohydrate consumption more than the M-CHO group (190 ± 50 g in M-CHO vs. 153 ± 39 g in H-CHO, p < 0.05), and this was especially pronounced for the mono- and disaccharides (86 ± 30 g in M-CHO vs. 65 ± 27 g in H-CHO, p < 0.05). Conclusion: A high relative carbohydrate intake before LRYGB, did not influence the change in body composition or diabetes status after surgery, despite a significantly lower total energy intake and less mono- and disaccharide consumption after surgery.

Association Between a Low-Carbohydrate Diet, Glycemic Control, and Quality of Life in Australian Adults Living With Type 1 Diabetes: A Pilot Study

ObjectiveTo examine if there is an association between a low-carbohydrate diet (LCD), glycemic control, and quality of life (QoL) in Australian adults with type 1 diabetes. MethodsThis single-group, pre-post, mixed methods (quantitative and qualitative) study was conducted in an outpatient tertiary hospital. Eligible participants were those aged ≥18 years, with type 1 diabetes for ≥1 year, and using multiple daily insulin injections. Participants followed a 12-week individualized LCD (<100 g/d). Daily glucose levels were monitored using a continuous glucose monitor. Glycated hemoglobin (HbA1c) and QoL were measured preintervention and postintervention. A post-hoc exploratory regression analysis determined whether changes in carbohydrate intake was associated with changes in HbA1c and QoL. Qualitative data collected postintervention explored participants’ perceptions relating to a LCD, glycemic control, and QoL. ResultsParticipants (n = 22) completed the 12-week LCD intervention. An LCD provided a statistically, significant improvement in HbA1c 0.83% (95% CI 0.32%-1.33%), P = .003 but did not impact QoL: estimated change 1.14 units (95% CI: −5.34 to 7.61); P = .72. The post-hoc exploratory regression analysis showed that participants with poorer baseline glycemic control were more likely to respond to an LCD resulting in significant reductions in HbA1c. Participant perceptions relating to the study variables were mixed. ConclusionsAn LCD (<100 g/d) is a potentially effective and safe strategy to improve glycemic control without negatively effecting QoL in Australian adults with type 1 diabetes.

Examining the Effect of a 1-yr Lifestyle Intervention on Cardiometabolic and Inflammatory Biomarkers in Youth with Overweight or Obesity: A Pilot Study

ABSTRACT Physical activity and healthy eating are key to managing overweight/obesity but may not induce adequate improvements in biomarkers of health. Characterizing the effect of behavioral interventions on cardiometabolic and inflammatory biomarkers could help guide a personalized approach to lifestyle change; however, little is known about the relationship between lifestyle changes and biomarkers in youth with overweight/obesity. We sought to determine how cardiometabolic and inflammatory biomarkers change in metabolically healthy youth with overweight/obesity in response to a 1-yr-long physical activity and healthy eating lifestyle intervention. Fifty children (8.7 ± 1.1 yr, 52% male) provided complete data on physical activity, dietary intake, body composition, blood pressure, and fasting biomarkers (insulin, glucose, triglycerides, cholesterol, adiponectin, resistin, interleukin-6, and tumor necrosis factor α). A series of t-tests were conducted to assess change over time, with a series of ordinary least squares regressions conducted to examine the association between change in markers responsive to the intervention and changes in macronutrient intake and physical activity, controlling for sex and change in percent body fat. Significant health-enhancing changes were seen over 1 yr in moderate and vigorous physical activity, percent body fat, macronutrient intake, insulin, and inflammatory markers, whereas sedentary time and resistin increased and light physical activity decreased. When change in biomarkers was regressed on behavior changes and change in percent body fat, changes in carbohydrate intake and body fat predicted change in insulin, change in fat intake predicted change in adiponectin, and change in carbohydrate intake predicted interleukin-6 in fully adjusted models. A lifestyle intervention over 1 yr was effective in producing positive changes in moderate and vigorous physical activity, macronutrient intake, insulin, and inflammatory markers, but these changes were not associated with changes in physical activity. Macronutrient changes were modestly associated with changes in insulin, resistin, and interleukin-6.

Long-term dietary intake from infancy to late adolescence is associated with gut microbiota composition in young adulthood

ABSTRACTBackgroundGut microbiota composition as influenced by long-term diet may be associated with the risk of adult chronic diseases. Thus, establishing the relation of long-term diet, particularly starting from early life, with adult microbiota composition would be an important research advance.ObjectiveWe aimed to investigate the association of long-term intake of energy, carbohydrate, fiber, protein, and fat from infancy to late adolescence with microbiota composition in adulthood.MethodsWithin the prospective DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, we sampled stool 1 or 2 times within 1 y from 128 adults (median age: 29 y). Microbiota composition was profiled by 16S ribosomal RNA sequencing. Annual dietary records from age 1 to 18 y were retrieved. We estimated trajectories of energy, energy-adjusted carbohydrate, fiber, protein, and fat intake with multilevel models, producing predicted intake at age 1 y and rates of change in intake. A multivariate, zero-inflated, logistic-normal model was used to model the association between intake trajectories and the composition of 158 genera in single-sampled individuals. Associations found in this model were confirmed in double-sampled individuals using a zero-inflated Beta regression model.ResultsAdjusting for covariates and temporal differences in microbiota composition, long-term carbohydrate intake was associated with 3 genera. Specifically, carbohydrate intake at age 1 y was negatively associated with Phascolarctobacterium [coefficient = −4.31; false discovery rate (FDR)–adjusted P = 0.006] and positively associated with Dialister (coefficient = 3.06; FDR-adjusted P = 0.003), and the rate of change in carbohydrate intake was positively associated with Desulfovibrio (coefficient = 13.16; FDR-adjusted P = 0.00039). Energy and other macronutrients were not associated with any genus.ConclusionsThis work links long-term carbohydrate intake to microbiota composition. Considering the associations of high carbohydrate intake and microbiota composition with some diseases, these findings could inform the development of gut microbiota–targeted dietary recommendations for disease prevention.

A carbohydrate-restricted diet for patients with irritable bowel syndrome lowers serum C-peptide, insulin, and leptin without any correlation with symptom reduction

Alterations in gut endocrine cells and hormone levels have been measured in patients with irritable bowel syndrome (IBS). The hypothesis of the present study was that hormone levels would change after 4 weeks of a starch- and sucrose-reduced diet (SSRD) intervention corresponding to decreased carbohydrate intake and symptoms. Among 105 IBS patients from primary and tertiary healthcare, 80 were randomized to SSRD, while 25 followed their ordinary diet. Food diaries, Rome IV, and IBS-symptom severity score (IBS-SSS) questionnaires were completed, and blood samples were collected at baseline and after the intervention. Serum C-peptide, gastric inhibitory peptide, glucagon, glucagon-like peptide-1, insulin, leptin, luteinizing hormone, polypeptide YY, and glucose were measured, along with the prevalence of autoantibodies against gonadotropin-releasing hormone; its precursor, progonadoliberin-2, and receptor; and tenascin C. Carbohydrate intake was lower in the intervention group than in controls at week 4 (median: 88 [66-128] g vs 182 [89-224] g; P < .001). The change in carbohydrate intake, adjusted for weight, was associated with a decrease in C-peptide (β: 14.43; 95% confidence interval [CI]: 4.12-24.75) and insulin (β: 0.18; 95% CI: 0.04-0.32) levels. Glucose levels remained unchanged. The IBS-SSS scores were lower in the intervention group but not in controls (P < .001), without any association with changes in hormone concentrations. There was no difference in autoantibody prevalence between patients and healthy controls. In conclusion, the hypothesis that reduced carbohydrate intake corresponded to altered hormonal levels in IBS was accepted; however, there was no relationship between hormonal concentrations and symptoms.

From carbohydrates to fat: Trends in food intake among Swedish nutrition students from 2002 to 2017.

Earlier studies have implied a change in dietary habits of the Swedish population towards a low carbohydrate, high fat diet. Questions have been raised about the development in recent years and potential health effects. We have investigated the dietary intake of Swedish female students enrolled in a university nutrition course between 2002 and 2017. The students carried out self-reporting of all food and drink intake over one weekday and one weekend day. Intake of macronutrients (E%) and micronutrients were calculated for the whole period while statistical analysis was performed for changes between 2009 and 2017 (729 women). Results showed significant changes in carbohydrate intake (from 47.0 to 41.4 E%) and fat intake (from 31.7 to 37.5 E%). Carbohydrate intake was significantly lower than the Nordic Nutrition Recommendations (45-60 E%). However, daily fiber intake remains high (3.0 g/MJ) in a national context, and intake of vitamin D and folate appears to increase during the period. The results suggest that the observed national transition from carbohydrate to fat intake persists, and that it might be especially evident among individuals interested in food and nutrition. Considering the fiber and micronutrient intake, the change is not necessarily unfavorable for this particular group.

Changes in blood lipid concentrations associated with changes in intake of dietary saturated fat in the context of a healthy low-carbohydrate weight-loss diet: a secondary analysis of the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) trial

For low-carbohydrate diets, a public health approach has focused on the replacement of carbohydrates with unsaturated fats. However, little research exists on the impacts of saturated fat intake on the lipid profile in the context of whole-food-based low-carbohydrate weight-loss diets. The primary aim of this secondary analysis of the DIETFITS weight loss trial was to evaluate the associations between changes in percentage of dietary saturated fatty acid intake (%SFA) and changes in low-density lipoproteins, high-density lipoproteins, and triglyceride concentrations for those following a healthy low-carbohydrate (HLC) diet. The secondary aim was to examine these associations specifically for HLC dieters who had the highest 12-month increases in %SFA. In the DIETFITS trial, 609 generally healthy adults, aged 18-50 years, with body mass indices of 28-40 kg/m2 were randomly assigned to a healthy low-fat (HLF) or HLC diet for 12 months. In this analysis, linear regression, both without and with adjustment for potential confounders, was used to measure the association between 12-month change in %SFA and blood lipids in 208 HLC participants with complete diet and blood lipid data. Participants consumed an average of 12-18% of calories from SFA. An increase of %SFA, without significant changes in absolute saturated fat intake, over 12 months was associated with a statistically significant decrease in triglycerides in the context of a weight-loss study in which participants simultaneously decreased carbohydrate intake. The association between increase in %SFA and decrease in triglycerides was no longer significant when adjusting for 12-month change in carbohydrate intake, suggesting carbohydrate intake may be a mediator of this relationship. Those on a low-carbohydrate weight-loss diet who increase their percentage intake of dietary saturated fat may improve their overall lipid profile provided they focus on a high-quality diet and lower their intakes of both calories and refined carbohydrates. This trial was registered at clinicaltrials.gov as NCT01826591.

Positive Changes in Blood Lipid Profiles, Nutrition Knowledge, and Dietary Taurine Intake After 8-Week Nutrition Education Program in Low-Income Korean Children.

Taurine has been reported to play a key role in the growth and development of children's brains and nerves. Incorrect dietary habits and unbalanced nutrient intakes may be caused by socio-environmental and economic factors in low-income children. This study was conducted to investigate changes in blood lipid profiles, nutrition knowledge, dietary attitudes, and intakes of dietary taurine and nutrients after an 8-week nutrition education program (NEP) in low-income Korean children. In this intervention study, nutrition education, exercise, and nutrition counseling were conducted for 8-weeks in 22 low-income children (11-13years old, 9males and 13females) at community child center located in Incheon, Korea. Changes after the NEP were evaluated using a one group pretest-posttest design. Statistical analysis was performed using SPSS 20.0. After the 8-week NEP, there was a significant decrease in the blood triglyceride level of female students (p<0.01). As for nutrition knowledge, there were significant increases in the subscore of sugars and sodium in foods consumed by male students (p<0.05), total score of nutrition knowledge (p<0.01), subscore of sugars and sodium in foods (p<0.01), and fat content of foods and adequate dietary intake in female students (p<0.05). Dietary attitudes did not change. There were significant increases in intakes of dietary taurine, vitamin B6 (p<0.01), and dietary fiber (p<0.05) in female students after the NEP. There were significantly positive correlations between changes in dietary taurine intake and dietary attitudes as well as between changes in carbohydrate intake and total cholesterol level among all the subjects. Therefore, nutrition education to promote balanced nutrient intake and dietary attitudes for optimal growth and development of low-income children is needed.

Changes in Types of Dietary Fats Influence Long-term Weight Change in US Women and Men

BackgroundThe relation between dietary fat intake and body weight remains controversial. Few studies have examined long-term changes in types of dietary fat and weight change in longitudinal studies. ObjectiveThe objective of this study was to examine associations between intake of different types of fat and long-term weight change in US women and men. MethodsThe association between changes in consumption of varying types of fat and weight change was examined every 4 y through the use of multivariate models adjusted for age, baseline body mass index, and change in percentage energy from protein, intake of cereal fiber, fruits, and vegetables, alcohol use, and other lifestyle covariates in 3 prospective US cohorts, including 121,335 men and women free of diabetes, cardiovascular disease, cancer, or obesity over a 20- to 24-y follow-up. Dietary intakes and body weight were assessed via validated questionnaires. Cohort-specific results were pooled with the use of a random-effect meta-analysis. ResultsCompared with equivalent changes in carbohydrate intake, a 5% increase in energy from saturated fatty acid (SFA) and a 1% increase in energy from trans-fat were associated with 0.61 kg (95% CI: 0.54, 0.68 kg) and 0.69 kg (95% CI: 0.56, 0.84 kg) greater weight gain per 4-y period, respectively. A 5% increase in energy from polyunsaturated fatty acid (PUFA) was associated with less weight gain (−0.55 kg; 95% CI: −0.81, −0.29 kg). Increased intake of monounsaturated fatty acid (MUFA) from animal sources by 1% was associated with weight gain of 0.29 kg (95% CI: 0.25, 0.33 kg), whereas MUFA from plant sources was not associated with weight gain. ConclusionsDifferent dietary fats have divergent associations with long-term weight change in US men and women. Replacing saturated and trans-fats with unsaturated fats, especially PUFAs, contributes to the prevention of age-related weight gain. These trials were registered at clinicaltrials.gov as NCT00005152 and NCT00005182.

A Plant-Based High-Carbohydrate, Low-Fat Diet in Overweight Individuals in a 16-Week Randomized Clinical Trial: The Role of Carbohydrates.

The effects of carbohydrates on body weight and insulin sensitivity are controversial. In this 16-week randomized clinical trial, we tested the role of a low-fat, plant-based diet on body weight, body composition and insulin resistance. As a part of this trial, we investigated the role of changes in carbohydrate intake on body composition and insulin resistance. Participants (n = 75) were randomized to follow a plant-based high-carbohydrate, low-fat (vegan) diet (n = 38) or to maintain their current diet (n = 37). Dual-energy X-ray absorptiometry was used to measure body composition. Insulin resistance was assessed with the Homeostasis Model Assessment (HOMA-IR) index. A repeated measure ANOVA model was used to test the between-group differences from baseline to 16 weeks. A linear regression model was used to test the relationship between carbohydrate intake, and body composition and insulin resistance. Weight decreased significantly in the vegan group (treatment effect −6.5 [95% CI −8.9 to −4.1] kg; Gxt, p < 0.001). Fat mass was reduced in the vegan group (treatment effect −4.3 [95% CI −5.4 to −3.2] kg; Gxt, p < 0.001). HOMA-IR was reduced significantly in the vegan group (treatment effect −1.0 [95% CI −1.2 to −0.8]; Gxt, p = 0.004). Changes in consumption of carbohydrate, as a percentage of energy, correlated negatively with changes in BMI (r = −0.53, p < 0.001), fat mass (r = −0.55, p < 0.001), volume of visceral fat (r = −0.35, p = 0.006), and HOMA (r = −0.27, p = 0.04). These associations remained significant after adjustment for energy intake. Changes in consumption of total and insoluble fiber correlated negatively with changes in BMI (r = −0.43, p < 0.001; and r = −0.46, p < 0.001, respectively), fat mass (r = −0.42, p < 0.001; and r = −0.46, p < 0.001, respectively), and volume of visceral fat (r = −0.29, p = 0.03; and r = −0.32, p = 0.01, respectively). The associations between total and insoluble fiber and changes in BMI and fat mass remained significant even after adjustment for energy intake. Increased carbohydrate and fiber intake, as part of a plant-based high-carbohydrate, low-fat diet, are associated with beneficial effects on weight, body composition, and insulin resistance.

Abstract P220: Elevated De Novo Lipogenesis Fatty Acids and Lower Omega-6 Fatty Acids Are Associated With Markers of Insulin Resistance and Respond to Changes in Dietary Carbohydrate Intake in Overweight Individuals on Weight Loss Diets

Background: High blood levels of certain fatty acids (FAs) in the de novo lipogenesis pathway (DNL; i.e., 16:0, cis-16:1n7) and low levels of omega-6 FAs (n-6 FA; i.e., 18:2n6) have been related to increased risk for type 2 diabetes. We hypothesized that individuals with insulin resistance (IR) would have higher DNL and lower n-6 FA plasma levels than insulin sensitive (IS) individuals, and that DNL FA levels would decrease on a low-carbohydrate (LC) diet and not change on a low-fat (LF) diet. Methods: Plasma FAs were measured as a % of total FA in subjects (n=61) with varying degrees of obesity and IR before and after 6 months of LF or LC weight loss diets. IR metrics were calculated pre- and post from oral glucose tolerance tests and fasting blood samples. FA medians (Interquartile Range), Spearman correlations (R) and Mann-Whitney test results are presented. Results: All differences shown are significant at P&lt;0.05 unless reported as not significant (NS). Compared to the IS group, IR individuals had higher 16:0 (IR: 22.9% [22.2, 24.3] vs IS: 21.7% [20.2, 22.5]) and 16:1n7 (IR: 1.8% [1.4, 2.2] vs IS: 1.3% [1.1, 1.6]), and lower 18:2n6 (IR: 30.8% [27.8, 31.6] vs IS: 32.5% [30.0, 34.6]) levels at baseline. 16:0 and 16:1n7 were directly related to BMI (0.40, 0.28), fasting insulin (0.40, 0.33), HOMA-IR (0.40, 0.43), TG:HDL (0.38, NS) and indirectly to Matsuda Index (-0.35, -0.34). 18:2n6 was directly related to the Matsuda Index (0.35) and indirectly to HOMA-IR (-0.37) and TG:HDL (-0.45). Diet x IR status analyses were not significant, thus FA changes on LC and LF diets were compared. 16:1n7 decreased on the LC diet and did not change on the LF diet (LC: -0.5% [-0.7, -0.3] vs LF: -0.1% [-0.3, 0.2]). 18:2n6 levels increased on the LC diet and decreased on the LF diet (LC: 0.9% [-0.3, 2.7] vs LF: -0.5% [-2.4, 0.6]). Changes in dietary carbohydrate (% of calories) correlated with changes in 16:1n7 directly (0.38) and 18:2n6 indirectly (-0.37). Changes in 16:1n7 were directly related to changes in weight (0.55) and TG:HDL (0.65), and changes in 18:2n6 were indirectly related to TG:HDL changes (-0.51). Conclusions: Elevated plasma DNL FA and lower 18:2n6 were evident in IR vs. IS individuals, and individual markers of IR were related to FA levels accordingly. DNL and 18:2n-6 responded to changes in carbohydrate intake. FA patterns may be a useful tool to identify IR individuals and track carbohydrate consumption.

Risk of breast cancer recurrence associated with carbohydrate intake and tissue expression of IGFI receptor.

The insulin-like growth factor-I (IGFI) receptor is a potential target for breast cancer treatment and may be influenced by dietary intake. Nested, case-control study of 265 postmenopausal breast cancer survivors; primary breast cancer tissue was stained to determine IGFI receptor status. Change in carbohydrate intake from baseline to year 1 of study was estimated from 24-hour dietary recalls. Breast cancer recurrence cases (91) were matched to two controls (n = 174) on disease and study characteristics and counter matched on change in carbohydrate intake. Weighted conditional logistic regression models fit the risk of recurrence on IGFI receptor status and dietary change. Half of the tumors were IGFI receptor positive. Increased risk of recurrence was associated with IGFI receptor-positive status [HR 1.7; 95% confidence interval (CI), 1.2-2.5] and, separately, with a stable/increased intake of carbohydrates (HR 2.0; 95% CI, 1.3-5.0). There was a borderline significant interaction between those two variables (P = 0.11). Specifically, carbohydrate intake had no significant impact on risk of recurrence among women who were receptor negative, yet increased the risk of recurrence by more than 5-fold among women who were receptor positive (HR 5.5; 95% CI, 1.8-16.3). Among women whose tumor tissue is positive for the IGFI receptor, reducing carbohydrate intake after diagnosis could reduce the risk of breast cancer recurrence. These findings need replication in a larger sample. This is the first study to suggest that it may be possible to personalize dietary recommendations for breast cancer survivors based on molecular characteristics of their primary tumor tissue. .

P3-09-01: Change in Carbohydrate Intake and Breast Cancer Prognosis.

Abstract Breast tumors over express insulin-like-growth-factor receptors (IGF-IR), and levels of expression may be inversely related to tumor grade. Dietary factors, particularly carbohydrate intake, may stimulate activation of IGF-1R and affect prognosis. METHODS: Data are from N=2,651 women in the Women's Healthy Eating and Living (WHEL) Dietary Intervention trial, a plant based intervention trial that did not have a carbohydrate goal. All women were diagnosed with breast cancer within the previous 4 years. Carbohydrate dietary intake data were extracted from multiple 24-hour dietary recalls at study entry and one year, and were compared by recurrence status. Time to recurrence was modeled on year-one change in carbohydrate intake adjusted for baseline intake, menopausal status, and disease, treatment, and study characteristics. RESULTS: Baseline carbohydrate intake was 233 g/day. Women who recurred had a mean increase in carbohydrate intake over the first year, compared to those who did not recur (2.3 vs. −2.7 g/day; p=0.188). Change in starch intakes accounted for 48% of the change in carbohydrate intake (R-squared: 48%; p&amp;lt;0.001). Baseline starch intake did not differ by recurrence status (95.8 g/day; p=0.219). Mean year-one change in starch intake was −4.1 g/day among women who recurred vs. −8.7 g/day among women who did not recur (p=0.015). Year-one change in starch intake was independent of the study intervention (p=0.326). In the adjusted model, a 5-g/day increase in starch related to a 3% increased risk of recurrence (HR=1.03; 95% CI 1.01 - 1.06; p=0.017). The increased risk was limited to women diagnosed with low grade tumors (Table 1). DISCUSSION: Dietary modifications targeting starch intake warrant further investigation as a preventive measure against breast cancer recurrence. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-09-01.

Adiponectin profiles are affected by chronic and acute changes in carbohydrate intake in healthy cats

Adiponectin is a key adipokine that regulates carbohydrate and lipid metabolism. It circulates in stable low (LMW) and high molecular weight (HMW) forms. The aims of this study were to characterize baseline adiponectin profiles (total, LMW and HMW multimers) in healthy cats and to assess the effects of varying dietary carbohydrate content on adiponectin profiles. Cats were maintained on a diet with moderate carbohydrate content (37% metabolisable energy [ME]) for 4weeks and then randomly allocated to either a low carbohydrate (19% ME) or high carbohydrate (52% ME) diet for 4weeks. Fasting and postprandial plasma adiponectin profiles were measured by ELISA and sucrose gradient/Western blot. After consuming the moderate carbohydrate diet for 4weeks, fasting total, HMW and LMW plasma adiponectin concentrations were 5.0±0.6, 2.5±0.5 and 2.6±0.2μg/mL, respectively. After changing to the low carbohydrate diet, fasting total adiponectin was unchanged but HMW adiponectin increased and LMW adiponectin decreased. No significant postprandial changes were observed. Cats consuming the high carbohydrate diet had increased fasting total and LMW adiponectin with no change in HMW adiponectin. In the postprandial state total adiponectin was reduced and there was a trend towards a decrease in HMW (p=0.086) but not LMW multimers. These data indicate that feline adiponectin multimer profiles are similar to those reported in other species and demonstrate that changes in plasma adiponectin occur in response to chronic and acute carbohydrate intake and these reflect differential changes in adiponectin multimers.

Prospective Randomized Controlled Trial to Evaluate Effectiveness of Registered Dietitian–Led Diabetes Management on Glycemic and Diet Control in a Primary Care Setting in Taiwan

OBJECTIVEIn this randomized controlled trial we evaluated the effect of registered dietitian–led management of diabetes on glycemic control and macronutrient intake in type 2 diabetic patients in primary care clinics in Taiwan and studied the association between changes in macronutrient intake and glycemic measures.RESEARCH DESIGN AND METHODSWe recruited 154 adult patients with type 2 diabetes and randomly assigned them to a routine care control group (n = 79) or a registered dietitian–led intervention group (n = 75) who received on-site diabetic self-management education every 3 months over 12 months.RESULTSOver the 1-year period, neither the intervention group (n = 75) nor the control group (n = 79) had significant changes in A1C, whereas the intervention patients with poorly controlled baseline A1C (≥7%) (n = 56) had significantly greater improvements in A1C and fasting plasma glucose than the control subjects (n = 60) (−0.7 vs. −0.2%, P = 0.034; −13.4 vs. 16.9 mg/dl, P = 0.007) during the same period. We also found significant net intervention-control group differences in overall energy intake (−229.06 ± 309.16 vs. 56.10 ± 309.41 kcal/day) and carbohydrate intake (−31.24 ± 61.53 vs. 7.15 ± 54.09 g/day) (P < 0.001) in patients with poorly controlled A1C. Multivariable adjusted modeling revealed an independent association between changes in carbohydrate intake and A1C in the intervention group (n = 56; β = 0.10, SEM = 0.033, P = 0.004).CONCLUSIONSOn-site registered dietitian–led management of diabetes can improve glycemic control in patients with poorly managed type 2 diabetes in primary care clinics in Taiwan. A reduction in carbohydrate intake may improve glycemic status.

The unique role of proprotein convertase subtilisin/kexin 9 in cholesterol homeostasis

The LDL receptor (LDLR) plays an essential role in the regulation of plasma (LDL) cholesterol concentrations by virtue of its ability to clear plasma LDL. Down-regulation of the LDLR by proprotein convertase subtilisin/kexin 9 (PCSK9) has recently emerged as a regulatory mechanism that controls plasma LDL cholesterol concentrations. Studies in which PCSK9 is over-expressed in mice, have demonstrated that PCSK9, by enhancing hepatic LDLR degradation, decreases the availability of the LDLR for LDL uptake, resulting in increased plasma LDL cholesterol levels. However, PCSK9 has also recently been shown to mediate down-regulation of surface receptors other than the LDLR, suggesting that it may have much broader roles than initially thought.

Beef and soy-based food supplements differentially affect serum lipoprotein-lipid profiles because of changes in carbohydrate intake and novel nutrient intake ratios in older men who resistive-train

Objective We examined if the predominant source of dietary protein influenced the lipoprotein-lipid profile in older men who performed resistive exercise training (RT). Design This is a 14-week, randomized, repeated-measures study with a 12-week period of RT with supplementation of different sources of dietary protein (beef and soy). Setting Nutrition, Metabolism, and Exercise Laboratory, Central Arkansas Veteran's Healthcare System, North Little Rock, Ark. Subjects Twenty-six healthy men were recruited, and 21 men (age 65 ± 5 years, body mass index 28.2 ± 2.6 kg/m 2) completed the study. Interventions For 14 weeks, all men were counseled to self-select a lacto-ovo-vegetarian diet. For 2 weeks (baseline), all men also consumed 0.6 g-protein/kg per day from portioned quantities of soy-based texturized vegetable protein foods. For the next 12 weeks, 11 men were randomized to continue with texturized vegetable protein foods (VEG group), whereas 10 men were randomized to receive 0.6 g-protein/kg per day from portioned quantities of beef (BEEF group) and continue their otherwise lacto-ovo-vegetarian diet. All men participated in RT 3 d/wk during this 12-week period. Assessments of upper and lower body muscle strength and power, serum lipoprotein-lipid profile, and dietary nutrient intakes were made at baseline and week 12 of RT (POST). Results The BEEF and VEG groups increased ( P < .05) overall muscle strength and muscle power with RT, with no differences between groups. From baseline to POST, the BEEF group had increased concentrations of high-density lipoprotein cholesterol ( P = .025; HDL-C), low-density lipoprotein cholesterol ( P = .027; LDL-C), and total cholesterol ( P = .015: CHOL), with no changes ( P > .05) in triacylglycerol (TG), the CHOL/HDL-C ratio, or the TG/HDL-C ratio. The VEG group did not experience within-group changes ( P > .05) in any lipoprotein-lipid parameter. At POST, the concentrations of HDL-C, LDL-C, and CHOL were greater in the BEEF group compared with the VEG group. There were significant interaction effects for HDL-C ( P = .004) and the TG/HDL-C ratio ( P = .022). Multiple regression analysis determined that, regardless of intervention, change in the saturated fat/fiber ratio (SF/fiber) predicted CHOL (adjusted R 2 = 0.34); the SF/fiber ratio predicted LDL-C (adjusted R 2 = 0.36); the cholesterol/fiber intake ratio predicted HDL-C (adjusted R 2 = 0.26), and the change in carbohydrate intake predicted the CHOL/HDL-C ratio (adjusted R 2 = 0.37) and TG (adjusted R 2 = 0.44). Conclusions These results suggest that the lipoprotein-lipid profile in these older men was differentially affected by supplementation with beef versus soy-based foods during RT. Regardless of group, the lipoprotein-lipid changes were predicted by differences in the SF/fiber ratio and cholesterol/fiber ratio and increases in carbohydrate intake over time.