Susan K. Raatz

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.

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.

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. Copyright

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.

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.

Noninvasive quantification of ascorbate and glutathione concentration in the elderly human brain

In this study, ascorbate (Asc) and glutathione (GSH) concentrations were quantified noninvasively using double‐edited 1H MRS at 4 T in the occipital cortex of healthy young [age (mean ± standard deviation) = 20.4 ± 1.4 years] and elderly (age = 76.6 ± 6.1 years) human subjects. Elderly subjects had a lower GSH concentration than younger subjects (p < 0.05). The Asc concentration was not significantly associated with age. Furthermore, the lactate (Lac) concentration was higher in elderly than young subjects. Lower GSH and higher Lac concentrations are indications of defective protection against oxidative damage and impaired mitochondrial respiration. The extent to which the observed concentration differences could be associated with physiological differences and methodological artifacts is discussed. In conclusion, GSH and Asc concentrations were compared noninvasively for the first time in young vs elderly subjects. Copyright

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.

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.

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.

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.