Serum β-carotene concentrations are associated with self-reported fatty acid intake in United States adults from the National Health and Examination Surveys

Bioavailability of dietary β‐carotene (BC) is dependent on dose, quantity, dispersion, and presence of fat in the diet. Fats are comprised of a variety of fatty acids, which may impact the bioavailability of carotenoids. However, there is a gap in research on whether specific fatty acid classes affect serum BC concentrations in population samples. The primary objective of this study was to assess the association between reported fat and fatty acid intake and serum BC concentrations utilizing data from the National Health and Nutrition Examination Surveys (NHANES) 2003–2006. Data from 3278 NHANES participants 20–85 years old were analyzed to estimate the relationships between serum BC concentrations and reported saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acid intakes. Multiple linear regression estimated ln(serum BC) based on reported fatty acid intakes adjusted for age, sex, race/ethnicity, and reported dietary BC intakes. Mean and standard error (SE) for serum BC concentrations were 14.31 ± 0.05 μg/dl. Means and SE for total fat, SFA, MUFA, and PUFA were 85.7 ± 1.3, 26.9 ± 0.4, 31.1 ± 0.5, and 17.8 ± 0.4 g, respectively. There was a significant trend for association between serum BC and reported total fat intakes (r = −0.002, p < 0.0001), but the association was not strong. Multiple linear regression showed positive associations between serum BC concentrations and higher reported dietary PUFA consumption. PUFA alpha‐linolenic acid intakes are positively associated with serum BC concentrations, while MUFA palmitoleic acid and SFA stearic acid were inversely associated with serum BC. The inverse association between MUFA and SFA suggests there may be multiple post‐digestion factors affecting serum carotenoid concentrations.

Reported nutrient intake over 7 years after Roux-en-Y gastric bypass in the Longitudinal Assessment of Bariatric Surgery-3 (LABS-3) psychosocial study

BACKGROUND

Bariatric surgery is the most effective therapy for severe obesity. It reduces gastric capacity and may modify regulation of appetite, satiety, insulin, and other physiologic processes, resulting in weight loss.

OBJECTIVE

Long-term data on postsurgical nutrient intake are lacking.

SETTING

The Longitudinal Assessment of Bariatric Surgery-3 psychosocial study.

METHODS

Reported dietary intake was assessed in a subset of participants (n = 72) of the Longitudinal Assessment of Bariatric Surgery-3 psychosocial study who underwent Roux-en-Y gastric bypass surgery. Two 24-hour diet recalls at presurgery and annual assessments over 7 years were obtained. Reported diets were evaluated for energy, macro- and micronutrient intake, and assessed for adequacy by comparison to the dietary reference intakes.

RESULTS

After surgery, reported intake of total energy, and all macronutrients were significantly reduced. At least a quarter of participants reported protein intake below the recommended dietary allowance. Over half of participants reported intake of several vitamins (C, D, A, E, thiamin, folate) and minerals (zinc, calcium) below recommended levels over 7 years. Compared with presurgery, reported energy intake was reduced over 7 years. This study was registered at ClinicalTrials.gov as NCT02495142.

CONCLUSIONS

The reduction in energy resulted in intakes below the dietary reference intakes for many micronutrients among the majority of participants and below the recommended dietary allowance for protein in a substantial subgroup. These data support continued long-term nutrition education, monitoring, and supplementation.

Concurrent validity of skin carotenoid status as a concentration biomarker of vegetable and fruit intake compared to multiple 24-h recalls and plasma carotenoid concentrations across one year: a cohort study

Background

Biological markers of vegetable and fruit (VF) intake are needed both for nutrition surveillance and for the evaluation of nutrition interventions. Optically assessed skin carotenoid status (SCS) has been proposed as a marker of intake but there are few published validity studies to date. Therefore, the objective of the study was to examine the concurrent validity of multiple methods of assessing VF intake cross-sectionally and seasonally over one year and to discuss the relative merits and limitations of each method.

Methods

Fifty-two 40–60 y old women completed a 1-year longitudinal study that included 1) SCS assessment using resonance Raman spectroscopy (RRS) and using pressure-mediated reflection spectroscopy (RS) at 12 timepoints, 2) thirty-six 24-h recalls using the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24; total 1866 recalls), and 3) plasma carotenoid concentrations measured every 3 months. Pearson correlation coefficients and mixed linear models were used to estimate pairwise correlations between RRS, RS, ASA24, and plasma carotenoids.

Results

RS and RRS were strongly correlated at baseline and over the year (r = 0.86 and 0.76; respectively, P < 0.001). RS was strongly correlated with plasma carotenoids at baseline (r = 0.70) and moderately across the year (r = 0.65), as was RRS (r = 0.77 and 0.69, respectively, all P < 0.001). At baseline, self-reported VF was weakly correlated with RRS (r = 0.33; P = 0.016), but not with RS or plasma carotenoids. Across the year, self-reported VF intake was weakly correlated with both RS (r = 0.37; P = 0.008), RRS (r = 0.37; P = 0.007), and with plasma carotenoids (r = 0.36; P < 0.008).

Conclusions

SCS as measured by RS and RRS is moderately to strongly correlated with plasma carotenoid concentrations both cross-sectionally and longitudinally, indicating that it can be a powerful tool to assess carotenoid-rich VF intake in populations.

Clinical trial registry

This trial was registered at ClinicalTrials.gov as NCT01674296.

Evaluation of a Rapid Assessment Questionnaire Using a Biomarker for Dietary Intake of n-3 Fatty Acids

While there is considerable evidence supporting health benefits of consuming diets high in omega-3 (n-3) fatty acids, there is no quick and effective tool to measure n-3 intake. The objective of this study was to evaluate the accuracy of a rapid assessment questionnaire (the Omega-3 Checklist) used to quantify intake of n-3 fatty acids. This was done by comparing n-3 intakes to blood biomarkers of n-3 exposure in a population of healthy men and women. In addition, a separate analysis was run including covariates age, sex, and weight, which have been shown to affect n-3 biomarker levels. Reported intake of eicosapentaenoic acid (EPA), docoshexaenoic acid (DHA), and EPA + DHA was correlated with erythrocyte EPA (Spearman's rank correlation r_s  = 0.51, p < 0.001), DHA (r_s  = 0.54, p < 0.001), and the Omega-3 Index (r_s  = 0.57, p < 0.001). These associations remained significant when controlling for age, sex, and weight. Therefore, the Omega-3 Checklist can be a useful, rapid assessment tool to estimate individuals' EPA and DHA intake.

Modeled replacement of traditional soybean and canola oil with high-oleic varieties increases monounsaturated fatty acid and reduces both saturated fatty acid and polyunsaturated fatty acid intake in the US adult population

BACKGROUND

High-oleic (HO) seed oils are being introduced as replacements for trans fatty acid (TFA)-containing fats and oils. Negative health effects associated with TFAs led to their removal from the US Generally Recognized As Safe list. HO oils formulated for use in food production may result in changes in fatty acid intake at population levels.

Objectives

The purposes of this study were to 1) identify major food sources of soybean oil (SO) and canola oil (CO), 2) estimate effects of replacing SO and CO with HO varieties on fatty acid intake overall and by age and sex strata, and 3) compare predicted intakes with the Dietary Reference Intakes and Adequate Intakes (AIs) for the essential fatty acids (EFAs) α-linolenic acid (ALA) and linoleic acid (LA).

Design

Food and nutrient intakes from NHANES waves 2007-2008, 2009-2010, 2011-2012, and 2013-2014 in 21,029 individuals aged ≥20 y were used to model dietary changes. We estimated the intake of fatty acid with the replacement of HO-SO and HO-CO for commodity SO and CO at 10%, 25%, and 50% and evaluated the potential for meeting the AI at these levels.

RESULTS

Each modeling scenario decreased saturated fatty acids (SFAs), although intakes remained greater than recommended for all age and sex groups. Models of all levels increased the intake of total monounsaturated fatty acids (MUFAs), especially oleic acid, and decreased the intake of total polyunsaturated fatty acids (PUFAs), particularly LA and ALA. Replacement of traditional with HO oils at 25-50% places specific adult age and sex groups at risk of not meeting the AI for LA and ALA.

Conclusions

The replacement of traditional oils with HO varieties will increase MUFA intake and reduce both SFA and PUFA intakes, including EFAs, and may place specific age and sex groups at risk of inadequate LA and ALA intake.

Mineral content of eggs differs with hen strain, age, and rearing environment

Egg nutrient quality is strongly influenced by hen diet but is also affected by rearing environment, hen strain, and hen age. The objective of the current study was to determine the effect of: 1) conventional battery cages, 2) enrichable cage systems, 3) enriched colony housing, 4) cage-free, and 5) free-range rearing systems on mineral concentrations of whole, dried egg (yolk and albumen combined) from TA Tetra White (TW) and Hy-Line Brown (HB) hens at 44, 68, and 88 wk of age. We hypothesized that mineral concentration of eggs would differ among rearing systems but not between strains or with hen age. Hens held in enriched colony housing systems produced eggs with 10% lower Mg and 11% lower Mn levels than conventional hens. Concentrations of Ca and Cu were higher (7 and 8%, respectively) in eggs from TW hens than from HB hens. Eggs from HB hens had 8% higher concentrations of Fe, 6% higher Mg and 5% higher Mn than TW hens. Mn was higher in eggs from 44-wk hens than from 68- or 88-wk hens (16 and 11%, respectively). Interaction effects between rearing environment and hen age were observed for K and Mn concentrations. Eggs from 68-wk hens in conventional rearing systems contained 14 to 21% more K than eggs from conventional hens at 44- and 88 wk and 14 to 18% more than eggs from 68-wk hens in other rearing systems. At 88 wk of age, hens in conventional rearing systems produced eggs with higher Mn concentration than hens in enrichable or enriched colony housing systems (22 and 23%, respectively). Interactions between rearing environment, hen strain, and hen age were observed for egg Zn levels among 44- and 68-wk hens but were not detectable among 88-wk hens regardless of rearing system or hen strain. Observed differences in egg mineral content in our study were small and are unlikely to have substantial impact on human nutrition.

Trends in linoleic acid intake in the United States adult population: NHANES 1999-2014

Linoleic acid (LA), the primary polyunsaturated fatty acid (PUFA) in the US diet, is an essential fatty acid. LA is available from a wide variety of foods, although it is primarily sourced from plant seed oils. Individual-level data on demography and food and nutrient intake were acquired from the NHANES waves 1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, 2009-2010, 2011-2012, and 2013-2014. Mean daily intake of (LA) was estimated for each survey wave overall, and by age, gender, educational attainment, race/ethnicity, and income-to-poverty ratio. Linear temporal (1999-2014) trends in LA intake were estimated using univariate linear regression tests, with P < 0.05 and a two-tailed distribution. We found that US adults meet intake recommendation for LA and observed a trend of increasing intake of LA in the US overall and by sub-categories of age, sex, education, race/ethnicity, and income-to-poverty ratio.

Smokers report lower intake of key nutrients than nonsmokers, yet both fall short of meeting recommended intakes

Smoking is a major risk factor in the development of preventable disease which may be due to a poorer diet and the reduced nutrient intake of smokers. Our objective was to compare and evaluate the reported intake of current smokers with that of nonsmokers among participants of a study evaluating stress and smoking. We hypothesized (1) that overall energy and nutrient intake would be reduced in smokers compared with nonsmokers and (2) that smokers would have increased noncompliance with Dietary Reference Intakes (DRIs). Men and women (smokers n=138, nonsmokers n=46) completed a 3-day diet record at baseline. Mean energy and nutrient intakes were stratified by smoking status and compared with DRI levels. The mean body mass index was 28.3±0.5kg/m2 for smokers and 27.2±1.0kg/m2 for nonsmokers. Compared with nonsmokers, the smokers reported lower intakes of energy, total polyunsaturated fatty acids, linolenic acid, docosahexaenoic acid, total sugars, calcium, iron, magnesium, phosphorus, potassium, vitamin C, riboflavin, niacin, pantothenic acid, vitamin B6, folate, vitamin A, and vitamin E. Smokers reported reduced compliance with the DRIs for iron, phosphorus, vitamin C, riboflavin, and folate compared with nonsmokers. Unlike other evaluations of smokers vs nonsmokers, we observed no difference in body weight between groups. Smokers and nonsmokers alike reported dietary intakes lower than the DRIs for many nutrients. However, the reported nutrient intake of the smokers was substantially lower than nonsmokers for key nutrients, and they were more likely to not comply with the DRIs for essential nutrients, placing them at increased risk of chronic disease.

Relationship of the Reported Intakes of Fat and Fatty Acids to Body Weight in US Adults

Dietary fat composition may modulate energy expenditure and body weight. Little is known about the relationship between fatty acid intake and body weight at a population level. The purposes of this study were to compare intakes of energy, macronutrients, and individual fatty acids across BMI categories (1) for the US adult population and, (2) by sociodemographic groups. Reported dietary intake data from the National Health and Nutrition Examination Survey (NHANES) and What We Eat in America (WWEIA) surveys in the years 2005-2012 were analyzed. Overall, we found that the reported intake of carbohydrate, protein, total fat, total saturated fat (as well as long-chain saturated fatty acids 14:0-18:0), and monounsaturated fatty acids (MUFAs) were positively associated with BMI; while lauric acid (a medium-chain saturated fatty acid, 12:0) and total polyunsaturated fatty acids (PUFAs) (as well as all individual PUFAs) were not associated with BMI. Non-Hispanic black individuals demonstrated a negative association between BMI and energy intake and a positive association between total PUFAs, linoleic acid (LA), α-linolenic acid (ALA) and BMI. Individuals with less than a high school education showed a negative association between BMI and DHA. Mexican-Americans reported intakes with no association between BMI and energy, any macronutrient, or individual fatty acids. These findings support those of experimental studies demonstrating fatty acid-dependent associations between dietary fatty acid composition and body weight. Notably, we observed divergent results for some sociodemographic groups which warrant further investigation.

Measures of Diet Quality across Calendar and Winter Holiday Seasons among Midlife Women: A 1-Year Longitudinal Study Using the Automated Self-Administered 24-Hour Recall

BACKGROUND

Systematic seasonal bias may confound efforts to estimate usual dietary intake and diet quality. Little is known about dietary quality over the winter holiday season.

OBJECTIVES

The aims of this study were to test for differences in intakes of energy, percentage of energy from macronutrients, fruits and vegetables, and diet quality measured using the Healthy Eating Index 2010 (HEI-2010) by calendar and winter holiday seasons.

DESIGN

Longitudinal cohort design.

PARTICIPANTS/SETTING

Data were derived from the Life in All Seasons study. Two cohorts of women aged 40 to 60 years (N=52) from the greater Grand Forks, ND, area were followed for 1 year each between July 2012 and July 2014. Each woman completed an online diet recall using the Automated Self-Administered 24-Hour Recall every 10 days during the year, with a 92% response rate.

STATISTICAL ANALYSES

Effects of calendar and winter holiday seasons on intakes of energy, percent energy from macronutrients, HEI-2010 total and component scores, and grams per day of individual fruits and vegetables were tested using mixed linear models.

RESULTS

The mean total HEI-2010 score was 60.1±1.4. There were seasonal differences in some HEI-2010 component scores, but not in total scores. More lettuce or mixed lettuce salad was consumed during summer than during winter (P=0.034), and more fresh tomatoes were consumed during summer and fall compared with winter (P=0.001). More corn, berries, peaches and nectarines, and melons (P<0.001) were consumed during summer. There was no seasonal difference in reported intakes of energy (P=0.793). The total HEI-2010 score for dietary intake observed over the winter holiday season was lower than the rest of the year (P<0.001). Reported energy intake was not different (P=0.228).

CONCLUSIONS

In this population, diet quality is significantly lower during the winter holiday period, but mostly consistent by season. Multiple recalls in any season can give a reasonable representation of usual overall diet quality throughout the year.

Consumption of Honey, Sucrose, and High-Fructose Corn Syrup Produces Similar Metabolic Effects in Glucose-Tolerant and -Intolerant Individuals

BACKGROUND

Public health recommendations call for a reduction in added sugars; however, controversy exists over whether all nutritive sweeteners produce similar metabolic effects.

OBJECTIVE

The objective was to compare the effects of the chronic consumption of 3 nutritive sweeteners [honey, sucrose, and high-fructose corn syrup containing 55% fructose (HFCS55)] on circulating glucose, insulin, lipids, and inflammatory markers; body weight; and blood pressure in individuals with normal glucose tolerance (GT) and those with impaired glucose tolerance (IGT).

METHODS

In a crossover design, participants consumed daily, in random order, 50 g carbohydrate from assigned sweeteners for 2 wk with a 2- to 4-wk washout period between treatments. Participants included 28 GT and 27 IGT volunteers with a mean age of 38.9 ± 3.6 y and 52.1 ± 2.7 y, respectively, and a body mass index (in kg/m(2)) of 26 ± 0.8 and 31.5 ± 1.0, respectively. Body weight, blood pressure (BP), serum inflammatory markers, lipids, fasting glucose and insulin, and oral-glucose-tolerance tests (OGTTs) were completed pre- and post-treatment. The OGTT incremental areas under the curve (iAUCs) for glucose and insulin were determined and homeostasis model assessment of insulin resistance (HOMA-IR) scores were calculated.

RESULTS

Body weight and serum glucose, insulin, inflammatory markers, and total and LDL-cholesterol concentrations were significantly higher in the IGT group than in the GT group at baseline. Glucose, insulin, HOMA-IR, and the OGTT iAUC for glucose or insulin did not differ by treatment, but all responses were significantly higher in the IGT group compared with the GT group. Body weight was unchanged by treatment. Systolic BP was unchanged, whereas diastolic BP was significantly lower in response to sugar intake across all treatments. An increase in high-sensitivity C-reactive protein (hsCRP) was observed in the IGT group in response to all sugars. No treatment effect was observed for interleukin 6. HDL cholesterol did not differ as a result of status or treatment. Triglyceride (TG) concentrations increased significantly from pre- to post-treatment in response to all sugars tested.

CONCLUSIONS

Daily intake of 50 g carbohydrate from honey, sucrose, or HFCS55 for 14 d resulted in similar effects on measures of glycemia, lipid metabolism, and inflammation. All 3 increased TG concentrations in both GT and IGT individuals and elevated glycemic and inflammatory responses in the latter. This trial was registered at clinicaltrials.gov as NCT01371266.

Nutritional adequacy of dietary intake in women with anorexia nervosa

Understanding nutrient intake of anorexia nervosa (AN) patients is essential for the treatment. Therefore, estimates of total energy and nutrient consumption were made in a group of young women (19 to 30 years) with restricting and binge purge subtypes of AN participating in an ecological momentary assessment study. Participants completed three nonconsecutive 24-hour diet recalls. Mean nutrient intakes were stratified by subtype and by quartiles of energy intake and compared to the age specific Dietary Reference Intake (DRI) levels, as well as to the reported intakes from the What We Eat In America (WWEIA) dietary survey 2011–2012. Reported intake was determined for energy, macronutrients, and micronutrients. The mean body mass index (BMI) for all participants was 17.2 ± 0.1 kg/m². Reported nutrient intake was insufficient for participants in quartiles 1–3 of both AN subtypes when compared to the DRIs. Intake reported by participants in quartile 4 of both subgroups met requirements for most nutrients and even met or exceeded estimated energy needs. Counseling of AN patients should be directed to total food consumption to improve energy intake and to reduce individual nutritional gaps.

Effect of black tea intake on blood cholesterol concentrations in individuals with mild hypercholesterolemia: a diet-controlled randomized trial

Habitual intake of black tea has been associated with relatively lower serum cholesterol concentrations in observational studies. However, clinical trial results evaluating the effects of black tea on serum cholesterol have been inconsistent. Several factors could explain these mixed results, in particular, uncontrolled confounding caused by lifestyle factors (eg, diet). This diet-controlled clinical trial estimates the effect of black tea flavonoid consumption on cholesterol concentrations in 57 borderline hypercholesterolemic individuals (total cholesterol concentrations between 190 and 260 mg/dL [4.9 and 6.7 mmol/L]). A double-blind, randomized crossover trial was conducted in Minneapolis, MN, from April 2002 through April 2004 in which key conditions were tightly controlled to minimize possible confounding. Participants consumed a controlled low-flavonoid diet plus 5 cups per day of black tea or tea-like placebo during two 4-week treatment periods. The flavonoid-free caffeinated placebo matched the tea in color and taste. Differences in cholesterol concentrations at the end of each treatment period were evaluated via linear mixed models. Differences among those treated with tea vs placebo were 3.43 mg/dL (0.09 mmol/L) (95% CI -7.08 to 13.94) for total cholesterol, -1.02 mg/dL (-0.03 mmol/L) (95% CI -11.34 to 9.30) for low-density lipoprotein cholesterol, 0.58 mg/dL (0.02 mmol/L) (95% CI -2.98 to 4.14) for high-density lipoprotein cholesterol, 15.22 mg/dL (0.17 mmol/L) (95% CI -40.91 to 71.35) for triglycerides, and -0.39 mg/dL (-0.01 mmol/L) (95% CI -11.16 to 10.38) for low-density lipoprotein plus high-density lipoprotein cholesterol fraction. The low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio decreased by -0.1 units (95% CI -0.41 to 0.21). No results were statistically or clinically significant. The intake of 5 cups of black tea per day did not alter the lipid profile of borderline hypercholesterolemic subjects significantly.

Validity of electronic diet recording nutrient estimates compared to dietitian analysis of diet records: randomized controlled trial

Background

Dietary intake assessment with diet records (DR) is a standard research and practice tool in nutrition. Manual entry and analysis of DR is time-consuming and expensive. New electronic tools for diet entry by clients and research participants may reduce the cost and effort of nutrient intake estimation.

Objective

To determine the validity of electronic diet recording, we compared responses to 3-day DR kept by Tap & Track software for the Apple iPod Touch and records kept on the Nutrihand website to DR coded and analyzed by a research dietitian into a customized US Department of Agriculture (USDA) nutrient analysis program, entitled GRAND (Grand Forks Research Analysis of Nutrient Data).

Methods

Adult participants (n=19) enrolled in a crossover-designed clinical trial. During each of two washout periods, participants kept a written 3-day DR. In addition, they were randomly assigned to enter their DR in a Web-based dietary analysis program (Nutrihand) or a handheld electronic device (Tap & Track). They completed an additional 3-day DR and the alternate electronic diet recording methods during the second washout. Entries resulted in 228 daily diet records or 12 for each of 19 participants. Means of nutrient intake were calculated for each method. Concordance of the intake estimates were determined by Bland-Altman plots. Coefficients of determination (R²) were calculated for each comparison to assess the strength of the linear relationship between methods.

Results

No significant differences were observed between the mean nutrient values for energy, carbohydrate, protein, fat, saturated fatty acids, total fiber, or sodium between the recorded DR analyzed in GRAND and either Nutrihand or Tap & Track, or for total sugars comparing GRAND and Tap & Track. Reported values for total sugars were significantly reduced (P<.05) comparing Nutrihand to GRAND. Coefficients of determination (R²) for Nutrihand and Tap & Track compared to DR entries into GRAND, respectively, were energy .56, .01; carbohydrate .58, .08; total fiber .65, .37; sugar .78, .41; protein .44, .03; fat .36, .03; saturated fatty acids .23, .03; sodium .20, .00; and for Nutrihand only for cholesterol .88; vitamin A .02; vitamin C .37; calcium .05; and iron .77. Bland-Altman analysis demonstrates high variability in individual responses for both electronic capture programs with higher 95% limits of agreement for dietary intake recorded on Tap & Track.

Conclusions

In comparison to dietitian-entered 3-day DR, electronic methods resulted in no significant difference in mean nutrient estimates but exhibited larger variability, particularly the Tap & Track program. However, electronic DR provided mean estimates of energy, macronutrients, and some micronutrients, which approximated those of the dietitian-analyzed DR and may be appropriate for dietary monitoring of groups. Electronic diet assessment methods have the potential to reduce the cost and burden of DR analysis for nutrition research and clinical practice.

Trial Registration

Clinicaltrials.gov NCT01183520; http://clinicaltrials.gov/ct2/show/NCT01183520 (Archived by WebCite at http://www.webcitation.org/6VSdYznKX).

Intake of seafood in the US varies by age, income, and education level but not by race-ethnicity

Current US federal dietary guidance recommends regular consumption of seafood (fish + shellfish) to promote health; however, little is known about how well Americans meet the guideline, particularly population subgroups that may be at risk for inadequate intake. The purposes of this study were to describe the prevalence of seafood consumption and, among consumers, the amounts of seafood eaten by sex, age group, income and education level, and race-ethnicity. Data from 15,407 adults aged 19+ participating in the 2005-2010 National Health and Nutrition Examination Surveys were analyzed using methods to account for sporadic intake of seafood. Over 80% of Americans reported consuming any seafood over the past 30 days, 74% reported consuming fish, and 54% reported eating shellfish. The percentages varied by socio-demographic group. Younger age and lower income and education levels were associated with lower odds of being a seafood consumer (p < 0.0001). Among those who reported eating seafood, the average amount eaten of any seafood was 158.2 ± 5.6 g/week. Among seafood consumers, women and individuals of lower age and education levels consumed less seafood. Approximately 80%-90% of seafood consumers did not meet seafood recommendations when needs were estimated by energy requirements. A great deal of work remains to move Americans toward seafood consumption at current recommended levels.

A comparison of the accuracy of self-reported intake with measured intake of a laboratory overeating episode in overweight and obese women with and without binge eating disorder

PURPOSE

Research has demonstrated significant underreporting of food intake in obese individuals with and without binge eating disorder (BED). An improved understanding of the accuracy of self-reported food intake is central to diagnosis of eating disorders and monitoring response to treatment. The purpose was to: (1) confirm those with BED consume significantly more kilocalories (kcal) than overweight/obese controls when instructed to overeat in the laboratory and (2) compare dietary recall data with measured intake.

METHODS

Fifteen women fulfilling BED criteria and 17 controls participated in an overeating episode and completed a 24-h dietary recall.

RESULTS

BED participants consumed significantly more kilocalories according to both methodologies. The BED group self-reported 90% of the measured intake compared to 98% for the control group. Mean differences between the methods indicated that on average both groups underreported intake; however, the mean difference between methods was significantly greater in the BED group.

CONCLUSIONS

Findings confirm that those with BED consume significantly more than controls during a laboratory binge and controls tended to be more accurate in recalling their intake 24 h later.

Perceived importance of dietary protein to prevent weight gain: a national survey among midlife women

OBJECTIVE

Evaluate reported use of the practice of "eating more protein" to prevent weight gain among midlife women.

DESIGN

Cross-sectional national survey.

PARTICIPANTS

One thousand eight hundred twenty-four midlife women (40-60 y) from the 9 United States geographic regions, primarily married (71%), white (76%), and well educated; half were premenopausal (49%).

OUTCOMES

Frequency of dietary practices to prevent weight gain, Weight Efficacy Lifestyle score, self-reported weight change and body mass index over the past 2 years, and current protein intake.

ANALYSIS

Linear regression models determined associations between weight change, protein intake, and reported use of the practice of "eating more protein" to prevent weight gain.

RESULTS

Most women correctly identified good protein sources, and the majority could indicate the daily percent dietary energy recommended from protein. "Eating more protein" to prevent weight gain was reported by 43% of women as a practice to prevent weight gain and was associated with weight loss over a 2-year period and with increased percent energy from protein.

CONCLUSIONS AND IMPLICATIONS

Reported use of the practice of "eating more protein" was associated with weight loss over 2 years. Education regarding dietary protein requirements may enhance the use of this practice.

Total dietary fat and omega-3 fatty acids have modest effects on urinary sex hormones in postmenopausal women

Background

Total fat and omega-3 fatty acids in the diet may affect breast cancer risk by altering estrogen metabolism. The purpose of this study was to elucidate the effects of differing total fat and omega-3 fatty acid content of diets on a panel of urinary estrogens and metabolites.

Findings

A controlled, cross-over feeding trial was conducted in postmenopausal women using three test diets: high fat diet (HF; 40% energy from fat), low fat diet (LF; 20% of energy from fat) and low fat, high omega-3 diet (LFn3; 23% energy from fat; 3% omega-3 fatty acids) for 8 week periods. Urinary hormone concentrations for 16 women were compared among diets using a linear mixed model, and within diet comparisons were made using paired t-tests. Urinary excretion of estrone was greater after the LF and LFn3 compared to the HF (P = 0.004). Estrone excretion was increased from baseline within the LF only (P = 0.02). Total estrone + estradiol + estriol increased from baseline with LF (P = 0.02) and was greater than the other two diets at 8 weeks (P = 0.03). There were no effects on estrogen metabolites, including the 2-hydroxy estrone:16α-hydroxy estrone ratio.

Conclusions

The results of this study indicate that urinary sex hormone metabolism was modestly altered in postmenopausal women by a low fat dietary intervention.

Issues of fish consumption for cardiovascular disease risk reduction

Increasing fish consumption is recommended for intake of omega-3 (n-3) fatty acids and to confer benefits for the risk reduction of cardiovascular disease (CVD). Most Americans are not achieving intake levels that comply with current recommendations. It is the goal of this review to provide an overview of the issues affecting this shortfall of intake. Herein we describe the relationship between fish intake and CVD risk reduction as well as the other nutritional contributions of fish to the diet. Currently recommended intake levels are described and estimates of fish consumption at a food disappearance and individual level are reported. Risk and benefit factors influencing the choice to consume fish are outlined. The multiple factors influencing fish availability from global capture and aquaculture are described as are other pertinent issues of fish nutrition, production, sustainability, and consumption patterns. This review highlights some of the work that needs to be carried out to meet the demand for fish and to positively affect intake levels to meet fish intake recommendations for CVD risk reduction.

Dose-dependent consumption of farmed Atlantic salmon (Salmo salar) increases plasma phospholipid n-3 fatty acids differentially

Enhanced n-3 fatty acid intake benefits cardiovascular disease (CVD) risk reduction. Increasing consumption at a population level may be better addressed by diet than through supplementation. However, limited data are available on the effect of the dose response to fish intake on plasma levels of n-3 fatty acids. To compare the effects of different doses of farmed Atlantic salmon on plasma phospholipid fatty acid proportions and CVD risk biomarkers (eg, glucose, insulin, homeostasis model of assessment-insulin resistance, high-sensitivity C-reactive protein, and interleukin-6) in healthy subjects we performed a randomized three-period crossover-designed trial (4-week treatment, 4- to 8-week washout) to compare the effects of twice per week consumption of farmed Atlantic salmon at doses of 90, 180, and 270 g in 19 apparently healthy men and women (mean age 40 to 65 years) and a body mass index between 25 and 34.9. All study visits were conducted at the US Department of Agriculture Agricultural Research Service Grand Forks Human Nutrition Research Center. Eicosapentaenoic acid and total n-3 concentrations were increased (P<0.05) by all treatments in a dose-response manner, with total n-3 of 8.03% ± 0.26% and 9.21% ± 0.26% for 180- and 270-g doses, respectively. Linoleic acid did not change in response to treatment, whereas arachidonic acid (P<0.05) and total n-6 fatty acids decreased dose dependently (<0.0001). The addition of farmed Atlantic salmon to the diet twice per week for 4 weeks at portions of 180 g and 270 g modifies phospholipid fatty acid proportions of n-3 and n-6 in a level associated with decreased risk for CVD.

Comparisons of energy intake and energy expenditure in overweight and obese women with and without binge eating disorder

The purpose of this study was to determine whether there are differences in energy intake or energy expenditure that distinguish overweight/obese women with and without binge eating disorder (BED). Seventeen overweight/obese women with BED and 17 overweight/obese controls completed random 24-h dietary recall interviews, and had total daily energy expenditure (TDEE) assessed by the doubly labeled water (DLW) technique with concurrent food log data collection. Participants received two baseline dual-energy X-ray absorptiometry (DXA) scans and had basal metabolic rate (BMR) and thermic effect of food (TEF) measured using indirect calorimetry. Results indicated no between group differences in TDEE, BMR, and TEF. As in our previous work, according to dietary recall data, the BED group had significantly higher caloric intake on days when they had binge eating episodes than on days when they did not (3,255 vs. 2,343 kcal). There was no difference between BED nonbinge day intake and control group intake (2,233 vs. 2,140 kcal). Similar results were found for food log data. Dietary recall data indicated a trend toward higher average daily intake in the BED group (2,587 vs. 2,140 kcal). Furthermore, when comparing TDEE to dietary recall and food log data, both groups displayed significant under-reporting of caloric intake of similar magnitudes ranging from 20 to 33%. Predicted energy requirements estimated via the Harris-Benedict equation (HBE) underestimated measured TDEE by 23-24%. Our data suggest that increased energy intake reported by BED individuals is due to increased food consumption and not metabolic or under-reporting differences.

Baking reduces prostaglandin, resolvin, and hydroxy-fatty acid content of farm-raised Atlantic salmon (Salmo salar)

The consumption of seafood enriched in n-3 polyunsaturated fatty acids (PUFA) is associated with a decreased risk of cardiovascular disease. Several n-3 oxidation products from eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (22:6n-3) have known protective effects in the vasculature. It is not known whether the consumption of cooked seafood enriched in n-3 PUFA causes appreciable consumption of lipid oxidation products. We tested the hypothesis that baking Atlantic salmon (Salmo salar) increases the level of n-3 and n-6 PUFA oxidation products over raw salmon. We measured the contents of several monohydroxy-fatty acids (MHFA), prostanoids, and resolvins. Our data demonstrate that baking did not change the overall total levels of MHFA. However, baking resulted in selective regioisomeric loss of hydroxy fatty acids from arachidonic acid (20:4n-6) and EPA, while significantly increasing hydroxyl-linoleic acid levels. The contents of prostanoids and resolvins were reduced several-fold with baking. The inclusion of a coating on the salmon prior to baking reduced the loss of some MHFA but had no effect on prostanoid losses incurred by baking. Baking did not decrease n-3 PUFA contents, indicating that baking of salmon is an acceptable means of preparation that does not alter the potential health benefits of high n-3 seafood consumption. The extent to which the levels of MHFA, prostanoids, and resolvins in the raw or baked fish have physiologic consequence for humans needs to be determined.

Varying protein source and quantity do not significantly improve weight loss, fat loss, or satiety in reduced energy diets among midlife adults

We hypothesized that a whey protein diet would result in greater weight loss and improved body composition compared with standard weight loss diets. Weight change, body composition, and renin-angiotensin aldosterone system activity in midlife adults were compared between diet groups. Eighteen subjects enrolled in a 5-month study of 8-week controlled food intake followed by 12-weeks ad libitum intake. Subjects were randomized to 1 of 3 treatment groups: control diet (CD) (55% carbohydrate/15% protein/30% fat), mixed protein (40% carbohydrate/30% protein/30% fat), or whey protein (WP) (40% carbohydrate/15% mixed protein/15% whey protein/30% fat). Measurements included weight, metabolic measures, body composition by dual-energy x-ray absorptiometry, and resting energy expenditure. No statistically significant differences in total weight loss or total fat loss were observed between treatments; however, a trend toward greater total weight loss (P = .08) and total fat loss (P = .09) was observed in the WP group compared with the CD group. Fat loss in the leg and gynoid regions was greater (P < .05) in the WP group than the CD group. No renin-angiotensin aldosterone system-mediated response was observed, but a decrease in systolic blood pressure was significantly greater (P < .05) in the WP group compared with the CD group. In summary, increased whey protein intake did not result in statistically significant differences in weight loss or in total fat loss, but significant differences in regional fat loss and in decreased blood pressure were observed in the WP group.

Effect of dietary fat and omega-3 fatty acids on urinary eicosanoids and sex hormone concentrations in postmenopausal women: a randomized controlled feeding trial

Substantial evidence relates increased sex hormone concentrations with increased breast cancer risk. Varying omega-3 (n-3) fatty acid (FA) intake may lead to alterations in eicosanoid balance and changes in circulating sex hormones that reduce risk. To clarify effects of dietary fat and n-3 FA intake on breast cancer risk markers, circulating sex hormones and urinary eicosanoids were measured in response to controlled feeding of diets designed to increase plasma concentrations of n-3 FA. A controlled cross-over feeding trial in postmenopausal women was conducted using 3 diets: high fat (HF; 40% energy from fat), low fat (LF; 20% energy from fat), and low fat plus n-3 FA (LFn3; 20% of energy from fat plus 3% of energy from n-3 FA) in 8-wk feeding periods. Plasma phospholipid fatty acid n-3 increased with the LFn3 relative to HF and LF (P < 0.0001). Plasma estradiol increased by 51% with HF (P = 0.03). Urinary prostaglandin E metabolite increased with HF relative to LF (P = 0.02) and urinary 11-dehydro-thromboxane B(2) increased with HF (P = 0.01). These results do not support a role of n-3 FA in the reduction of sex hormone levels.

Breakfast frequency and quality may affect glycemia and appetite in adults and children

Observational studies of breakfast frequency in children and adults suggest an inverse (protective) association between the frequency of eating breakfast and the risk for obesity and chronic diseases such as type 2 diabetes. More prospective studies with stronger designs are needed, as are experimental studies on this topic. In addition, above and beyond breakfast frequency, the roles of dietary quality and composition need to be studied in the context of eating or skipping breakfast. Experimental studies are also necessary to rigorously test causality and biological mechanisms. Therefore, we conducted 2 pilot experimental studies to examine some of the effects of breakfast skipping and breakfast composition on blood glucose and appetite in children and adults. Our results suggest that breakfast frequency and quality may be related in causal ways to appetite controls and blood sugar control, supporting the hypothesis that the breakfast meal and its quality may have important causal implications for the risk of obesity and type 2 diabetes.

Effect of fenugreek fiber on satiety, blood glucose and insulin response and energy intake in obese subjects

Eighteen healthy obese subjects participated in a single blind, randomized, crossover study of three test breakfasts, containing 0 g (control), 4 g or 8 g of isolated fenugreek fiber. Subjects recorded ratings of hunger, satiety, fullness and prospective food consumption using visual analog scales (VAS) every 30 min for 3.5 h. Postprandial blood glucose and insulin responses were measured. Energy intake from an ad libitum lunch buffet and for the remainder of the day was assessed. The 8 g dose of fenugreek fiber significantly increased mean ratings of satiety and fullness, and reduced ratings of hunger and prospective food consumption (P < 0.05). Palatability was significantly reduced with increasing doses of fenugreek fiber (P < 0.05). No differences were observed for area under the curve (AUC) for blood glucose among treatments. An increase in insulin AUC was found with 8 g fenugreek fiber. Energy intake at an ad libitum lunch buffet was significantly lower for 8 g than 4 g fenugreek fiber, but not significantly different from control, although there was a trend towards a lower intake (p = 0.11). No differences were observed for energy intake for the remainder of the day. Fenugreek fiber (8 g) significantly increased satiety and reduced energy intake at lunch, suggesting it may have short-term beneficial effects in obese subjects. Satiety results were not related to postprandial blood glucose.

Adolescent beverage habits and changes in weight over time: findings from Project EAT

BACKGROUND

Obesity in adolescence has been increasing in the past several decades. Beverage habits among adolescents include increased consumption of sugar-sweetened beverages and decreased consumption of milk.

OBJECTIVE

This study aimed to examine the association between beverage consumption and 5-y body weight change in 2294 adolescents.

DESIGN

Project EAT (Eating Among Teens) is a 5-y longitudinal study of eating patterns among adolescents. Surveys were completed in 1998-1999 (time 1) and in 2003-2004 (time 2). Multivariable linear regression was used to examine the association between beverage consumption at time 2 and change in body mass index from time 1 to time 2, with adjustments for age, socioeconomic status, race, cohort, physical activity, sedentary behavior, coffee, tea, time 1 body mass index, and beverage variables.

RESULTS

In prospective analyses, consumption of beverages was not associated with weight gain, except for consumption of low-calorie soft drinks (positive association, P = 0.002) and white milk (inverse association, P = 0.03), but these associations did not appear to be a monotonic linear dose-response relation. The positive association with low-calorie soft drinks was no longer present after adjustment for dieting and parental weight-related concerns, which suggests that the use of low-calorie soft drinks is a marker for more general dietary behaviors and weight concerns.

CONCLUSIONS

We showed no association between sugar-sweetened beverage consumption, juice consumption, and adolescent weight gain over a 5-y period. A direct association between diet beverages and weight gain appeared to be explained by dieting practices. Adolescents who consumed little or no white milk gained significantly more weight than their peers who consumed white milk. Future research that examines beverage habits and weight among adolescents should address portion sizes, adolescent maturation, and dieting behaviors.

Enhanced absorption of n-3 fatty acids from emulsified compared with encapsulated fish oil

Health benefits of n-3 fatty acids are well-established. However, consumption of adequate dietary sources of these fatty acids is inadequate. Oral fish oil supplements are an alternative means of consuming adequate long-chain n-3 fatty acids in individuals who do not consume sufficient dietary sources. However, palatability can present a problem with compliance. Emulsifying fish oil allows for production of a pleasant-tasting supplement and can enhance digestion and absorption of the fatty acids. We investigated the rate and extent of absorption of emulsified fish oil compared with capsular triglyceride fish oil supplements in humans. Participants subjectively rated palatability of these products. A randomized, crossover-designed, open-label trial was performed in which 10 healthy volunteers received emulsified fish oil and capsular triglyceride fish oil orally. Blood samples were collected at 0, 2, 4, 8, 24, and 48 hours to determine the absorption of individual fatty acids into plasma phospholipid fatty acids. At the completion of blood collection, subjects were asked to subjectively rate the tolerance and acceptability of the two supplements. During a 48-hour period, there was enhanced absorption of total n-3 and eicosapentaenoic acid (0.67%+/-0.16%, 0.45%+/-0.06%; P<0.01; 0.34%+/-0.05%, 0.23%+/-0.04%; P=0.05; emulsified fish oil and capsular triglyceride fish oil, respectively) observed for the emulsified fish oil treatment. Our findings indicate that a single dose of emulsified fish oil resulted in enhanced absorption of total n-3 eicosapentaenoic acid and docosahexaenoic acid as evidenced by changes in phospholipid fatty acids composition compared with the capsular triglyceride fish oil during the 48-hour observation period. Both supplements were subjectively rated and found to be well-tolerated by participants.

Monetary costs associated with bulimia

OBJECTIVE

The direct monetary costs for food and laxatives, diet pills, and diuretics used by individuals with bulimia nervosa (BN) have not been studied.

METHOD

Ten participants with a presenting clinical diagnosis of BN completed a 7-day food record at the outset of treatment in order to provide estimates of weekly and yearly monetary costs for food and associated symptoms.

RESULTS

Participants reported means of 3.6 purge episodes, 2.5 objective binge episodes, and 2.4 subjective binge eating episodes per week. Mean total food costs were $106.98/week (SD = $53.88) or $5,581.79/year (SD = $2,811.58). Costs associated with binge eating and purging were 32.7% of all food costs (average: $1,599.45/year).

CONCLUSION

Financial costs of bulimia symptoms are significant, and appear to constitute a substantial minority of all food spending by individuals with BN.

A comparison of energy intake and food selection during laboratory binge eating episodes in obese women with and without a binge eating disorder diagnosis

OBJECTIVE

The purpose of the study was to compare energy intake and food selection of laboratory binge eating episodes in obese women with and without binge eating disorder (BED).

METHOD

Twenty women, 12 meeting BED criteria, and 8 BMI and age matched obese controls, engaged in a laboratory binge eating episode.

RESULTS

BED participants consumed significantly more total food in kilocalories than the non-BED obese group and more kilocalories of fat. However, there were no differences between the groups in the proportion of calories from any macronutrient. There was a nonsignificant trend for the BED group to consume more total grams of food. During the binge, the BED group consumed more dairy products.

CONCLUSION

Results of the study confirmed that women with BED consumed significantly more total food in kilocalories than the non-BED obese women when they were allowed to have a binge eating episode in a laboratory setting.

Are your patients with risk of CVD getting the viscous soluble fiber they need?

A diet that includes 5 to 10 g/d of viscous soluble fiber reduces cardiovascular disease (CVD) events and death independent of baseline risk. Consuming foods rich in viscous soluble fiber reduces low-density lipoprotein cholesterol (LDL-C) blood levels 10% to 15% with expected reduction in CVD events by 10% to 15%. Routinely counsel adults at risk of CVD to promote a healthy diet: assess dietary fiber consumption; recommend specific foods rich in viscous soluble fiber; monitor LDL-C levels and encourage increased dietary fiber intake at follow-up visits; motivate patients to comply with recommendations.

Prospective study of changes in bone mineral density and turnover in children after hematopoietic cell transplantation

CONTEXT

Osteoporosis is common in adults after hematopoietic cell transplantation (HCT). The data on bone mineral density (BMD) in children after HCT are limited.

OBJECTIVE

The objective of the study was to determine the incidence, timing, magnitude, and possible predictors of bone loss in children after HCT.

PATIENTS AND DESIGN

The study population included 49 patients (age 5-18 yr) who were eligible to receive HCT at the University of Minnesota. The patients were evaluated at baseline, 100 d, 6 months, and 1 yr after HCT. Lumbar BMD (LBMD) was assessed by dual-energy x-ray absorptiometry.

RESULTS

The number of patients with osteopenia increased from 18% at baseline to 33% 1 yr after HCT, and with osteoporosis from 16-19%. Mean areal LBMD z-score decreased from -0.56 to -1.1 by 6 months (n = 27) and at 1 yr was -0.94 (n = 21), which was significant compared with standard normal distribution (P = 0.004 and P = 0.022, respectively). The absolute loss of bone mineral corresponded to a 5.3% reduction in areal LBMD and a 4.8% reduction in volumetric LBMD. The level of bone-specific alkaline phosphatase decreased by 30% by d 100 (P = 0.009), followed by recovery toward baseline by 6 months. The level of osteocalcin greater than 6.5 ng/ml at d 100 predicted recovery from the initial bone loss by 1 yr. A reduction in LBMD at 6 months correlated with a cumulative dose of glucocorticoids.

CONCLUSION

This study demonstrates that bone loss is common in children after HCT and is primarily due to suppression of bone formation. Further studies are necessary to validate osteocalcin as a predictive biomarker.

Effect of a high-carbohydrate versus a high--cis-monounsaturated fat diet on blood pressure in patients with type 2 diabetes

OBJECTIVE

To investigate whether blood pressure is different in type 2 diabetic patients on a diet rich in carbohydrates versus a diet rich in cis-monounsaturated fatty acids. Data on the dietary effects on these diets' glucose and lipid metabolism have been previously published.

RESEARCH DESIGN AND METHODS

The study compared the effect of feeding 42 type 2 diabetic patients a carefully controlled isoenergic high-carbohydrate (high-carb; 55% energy as carbohydrate, 30% as fat, and 10% as monounsaturated fat) and high-monounsaturated fat (high-mono; 45% energy as fat, 25% as monounsaturated fat, and 40% as carbohydrate) diet for 6 weeks each in a four-center, randomized, cross-over study on blood pressure. Twenty-one patients continued the diet they received during the second phase for an additional 8 weeks.

RESULTS

According to repeated-measures ANOVA, blood pressure during the last 3 days of each phase was similar after 6 weeks of the high-carb and high-mono diets (systolic blood pressure: 128 +/- 16 vs. 127 +/- 15 mmHg, P = 0.9; diastolic blood pressure: 75 +/- 7 vs. 75 +/- 8 mmHg, P = 0.7). However, after 14 weeks of the high-carb diet (n = 13), there was a significant increase in blood pressure compared with 6 weeks of the high-mono diet (systolic blood pressure: 132 +/- 13 vs. 126 +/- 11 mmHg, P = 0.04; diastolic blood pressure: 83 +/- 6 vs. 76 +/- 7 mmHg, P = 0.002). After 14 weeks of the high-mono diet (n = 8), the reduction in blood pressure was not significant compared with 6 weeks of the high-carb diet (systolic blood pressure: 118 +/- 14 vs. 121 +/- 16 mmHg, P = 0.4; diastolic blood pressure: 71 +/- 8 vs. 75 +/- 10 mmHg, P = 0.3).

CONCLUSION

Although the exchange of carbohydrates with monounsaturated fats may not affect blood pressure in the short term, long-term consumption of a high-carbohydrate diet may modestly raise blood pressure in type 2 diabetic patients.

Reduced glycemic index and glycemic load diets do not increase the effects of energy restriction on weight loss and insulin sensitivity in obese men and women

Reducing the dietary glycemic load and the glycemic index was proposed as a novel approach to weight reduction. A parallel-design, randomized 12-wk controlled feeding trial with a 24-wk follow-up phase was conducted to test the hypothesis that a hypocaloric diet designed to reduce the glycemic load and the glycemic index would result in greater sustained weight loss than other hypocaloric diets. Obese subjects (n = 29) were randomly assigned to 1 of 3 diets providing 3138 kJ less than estimated energy needs: high glycemic index (HGI), low glycemic index (LGI), or high fat (HF). For the first 12 wk, all food was provided to subjects (feeding phase). Subjects (n = 22) were instructed to follow the assigned diet for 24 additional weeks (free-living phase). Total body weight was obtained and body composition was assessed by skinfold measurements. Insulin sensitivity was assessed by the homeostasis model (HOMA). At 12 wk, weight changes from baseline were significant in all groups but not different among groups (-9.3 +/- 1.3 kg for the HGI diet, -9.9 +/- 1.4 kg for the LGI diet, and -8.4 +/- 1.5 kg for the HF diet). All groups improved in insulin sensitivity at the end of the feeding phase of the study. During the free-living phase, all groups maintained their initial weight loss and their improved insulin sensitivity. Weight loss and improved insulin sensitivity scores were independent of diet composition. In summary, lowering the glycemic load and glycemic index of weight reduction diets does not provide any added benefit to energy restriction in promoting weight loss in obese subjects.

Two-year outcome of a combination of weight loss therapies for type 2 diabetes

OBJECTIVE

To evaluate the effects over 2 years of a weight loss program combining several weight loss strategies on weight loss and diabetes control in overweight subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 59 overweight or obese individuals with type 2 diabetes were randomly assigned to either a combination therapy weight loss program for 2 years (C therapy) or a standard therapy weight loss program for 1 year followed by a combination therapy weight loss program in the 2nd year (S/C therapy). C therapy combined the use of meal replacement products, repetitive intermittent low-calorie-diet weeks, and pharmacologic therapy with sibutramine. Outcome measures included changes in weight, glycemic control, plasma lipids, blood pressure, and body composition over 2 years.

RESULTS

A total of 48 participants (23 in the C therapy group and 25 in the S/C therapy group) completed 2 years of study. After 2 years, the C therapy group had weight loss of 4.6 +/- 1.2 kg (P < 0.001) and a decrease in HbA(1c) of 0.5 +/- 0.3% (P = 0.08) from baseline. At 2 years, the C therapy group had significant reductions in BMI, fat mass, lean body mass, and systolic blood pressure. The S/C therapy group showed changes in weight and HbA(1c) in year 2 of the study that were similar to those demonstrated by the C therapy group in year 1.

CONCLUSIONS

This combination weight loss program resulted in significant weight loss and improved diabetes control over a 2-year period in overweight subjects with type 2 diabetes.

One-year outcome of a combination of weight loss therapies for subjects with type 2 diabetes: a randomized trial

OBJECTIVE

The purpose of this study was to evaluate the effects of a combination weight loss program using intermittent low-calorie diets, energy-controlled meal replacement products, and sibutramine on weight loss, diabetes control, and cardiovascular risk factors in overweight or obese subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Overweight or obese individuals with type 2 diabetes treated with diet or oral medication were randomly assigned to either a standard therapy or combination therapy group. Both groups received a standardized program to facilitate weight loss. The combination therapy group also received 10-15 mg sibutramine daily, low-calorie diets using meal replacement products for 1 week every 2 months, and between low-calorie diet weeks, once daily use of meal replacement product and snack bars to replace one usual meal and snack. Primary outcome measures were changes in body weight, glycemic control, plasma lipids, blood pressure, pulse, and body composition at 1 year.

RESULTS

At 1 year, combination therapy, compared with standard therapy, resulted in significantly more weight loss (-7.3 +/- 1.3 kg vs. -0.8 +/- 0.9 kg, P < 0.001) and reduction in HbA(1c) (-0.6 +/- 0.3 vs. 0.0 +/- 0.2%, P = 0.05). Combination therapy resulted in reduced requirement for diabetes medications and decreased fat mass and lean body mass. A 5-kg decrease in weight at 1 year was associated with a decrease of 0.4% in HbA(1c) (P = 0.006). Changes in fasting glucose, lipids, pulse, and blood pressure did not differ between groups.

CONCLUSIONS

This combination weight loss program resulted in greater weight loss and improved diabetes control compared with a standard weight loss program in overweight or obese subjects with type 2 diabetes.

Effect of whole grains on insulin sensitivity in overweight hyperinsulinemic adults

BACKGROUND

Epidemiologic studies have found whole-grain intake to be inversely associated with the risk of type 2 diabetes and heart disease.

OBJECTIVE

We tested the hypothesis that whole-grain consumption improves insulin sensitivity in overweight and obese adults.

DESIGN

This controlled experiment compared insulin sensitivity between diets (55% carbohydrate, 30% fat) including 6-10 servings/d of breakfast cereal, bread, rice, pasta, muffins, cookies, and snacks of either whole or refined grains. Total energy needs were estimated to maintain body weight. Eleven overweight or obese [body mass index (in kg/m(2)): 27-36] hyperinsulinemic adults aged 25-56 y participated in a randomized crossover design. At the end of each 6-wk diet period, the subjects consumed 355 mL (12 oz) of a liquid mixed meal, and blood samples were taken over 2 h. The next day a euglycemic hyperinsulinemic clamp test was administered.

RESULTS

Fasting insulin was 10% lower during consumption of the whole-grain than during consumption of the refined-grain diet (mean difference: -15 +/- 5.5 pmol/L; P = 0.03). After the whole-grain diet, the area under the 2-h insulin curve tended to be lower (-8832 pmol.min/L; 95% CI: -18720, 1062) than after the refined-grain diet. The rate of glucose infusion during the final 30 min of the clamp test was higher after the whole-grain diet (0.07 x 10(-4) mmol.kg(-1).min(-1) per pmol/L; 95% CI: 0.003 x 10(-4), 0.144 x 10(-4)).

CONCLUSION

Insulin sensitivity may be an important mechanism whereby whole-grain foods reduce the risk of type 2 diabetes and heart disease.

Total fat intake modifies plasma fatty acid composition in humans

Plasma fatty acid composition reflects dietary fatty acids. Whether the total fat content of the diet alters the fatty acid composition of plasma phospholipid, cholesteryl ester, triacylglycerol and free fatty acids is unknown. To evaluate the effects of low versus high fat diets on plasma fatty acids, a 12-wk, randomized, crossover, controlled feeding trial was conducted in healthy men and women with isoenergic low fat (20% energy) and high fat (45% energy) diets containing constant proportions of fatty acids. Ten subjects consumed one experimental diet for 28 d, their usual diet for 4 wk and the alternate experimental diet for 28 d. Endpoint measures of plasma fatty acids were determined at the end of each experimental period. The effects of the two diets were compared within subjects by analysis of variance. Plasma fatty acids (%) varied in response to total dietary fat with significantly greater total polyunsaturated fat, (n-6) and 18:2(n-6) levels in phospholipids and cholesteryl esters after high fat dietary consumption. The low fat diet was associated with significantly greater total (n-3) fatty acids, 20:5(n-3) and 22:6(n-3) levels in plasma phospholipid fatty acids and cholesteryl esters. Consumption of a low fat diet alters fatty acid patterns in a manner similar to that observed with feeding of (n-3) long-chain fatty acids. This change is likely related to decreased competition for the enzymes of elongation and desaturation, with reduced total intake of 18:2(n-6) favoring elongation and desaturation of available (n-3) fatty acids.

Effects of dietary fructose on plasma lipids in healthy subjects

BACKGROUND

About 9% of average dietary energy intake in the United States comes from fructose. Such a high consumption raises concern about the metabolic effects of this sugar.

OBJECTIVE

The objective of this study was to determine the effect of dietary fructose on plasma lipids.

DESIGN

The study was conducted in the General Clinical Research Center at Fairview-University of Minnesota Medical Center. The participants were 24 healthy adult volunteers (12 men and 12 women; 6 of each sex were aged <40 y and 6 of each sex were aged >/=40 y). All subjects received 2 isoenergetic study diets assigned by using a randomized, balanced crossover design. One diet provided 17% of energy as fructose. The other diet was sweetened with glucose and was nearly devoid of fructose. Each diet was fed for 6 wk. Both diets were composed of common foods and contained nearly identical amounts of carbohydrate, protein, fat, fiber, cholesterol, and saturated, monounsaturated, and polyunsaturated fatty acids. All meals were prepared in the metabolic kitchen of the General Clinical Research Center.

RESULTS

The responses to the study diets differed by sex. In men, the fructose diet produced significantly higher fasting, postprandial, and daylong plasma triacylglycerol concentrations than did the glucose diet. The daylong plasma triacylglycerol concentration after 6 wk of the fructose diet was 32% greater in men than the corresponding concentration during the glucose diet (P: < 0.001). The fructose diet had no significant effect on fasting or postprandial plasma triacylglycerol concentrations in women. The fructose diet also had no persistent effect on fasting plasma cholesterol, HDL cholesterol, or LDL cholesterol in either men or women.

CONCLUSIONS

Dietary fructose was associated with increased fasting and postprandial plasma triacylglycerol concentrations in men. Diets high in added fructose may be undesirable, particularly for men. Glucose may be a suitable replacement sugar.

Chronic treatment with phentermine combined with fenfluramine lowers plasma serotonin

As expected on the basis of published research in both humans and animals, treatment with phentermine/fenfluramine lowers plasma 5-hydroxytryptamine [corrected], whereas treatment with phentermine had no significant effect. In light of these findings, future research should focus on mechanisms other than increased plasma 5-hydroxytryptamine [corrected] to explain how fenfluramine increases the risk of primary pulmonary hypertension and valvular heart disease.