Diet Beef Research Articles

Nutrient contribution of total and lean beef in diets of US children and adolescents: National Health and Nutrition Examination Survey 1999–2004

This study examined the nutritional contribution of total beef and lean beef (LB) to the diet of US children and adolescents using the US Department of Agriculture definition of LB as defined in MyPyramid. Twenty-four hour dietary recall data from children 4–8 years of age [y] (n = 2474), 9–13 y (n = 3273), and adolescents 14–18 y (n = 4044) participating in the NHANES 1999–2004 were assessed. LB was defined as beef with ≤ 9.28 grams [g] fat/100 g (excess was discretionary fat). Means and standard errors were determined using appropriate sample weights. Consumption of LB contributed significantly to intake of protein and many key nutrients such as vitamins B6 and B12, zinc, iron, niacin, phosphorus, and potassium by US children and adolescents without providing significantly to intakes of total fat, saturated fatty acids, or sodium.

Nutritional Contribution of Lean Beef in Diets of Adults: National Health and Nutrition Examination Survey, 1999-2004

Nutritional Contribution of Lean Beef in Diets of Adults: National Health and Nutrition Examination Survey, 1999-2004

Nutritional Contribution of Lean Beef in Diets of Children (9‐13 Years): National Health and Nutrition Examination Survey, 1999‐2004

NHANES, 1999‐2004, 24‐hr dietary recalls were used to examine the contribution of lean beef (LB) to total nutrient intake in diets of children 9‐13 years (n=3,273), and determine dietary intake differences between LB consumers and non‐consumers.. LB was defined by MyPyramid Equivalents Database as beef contributing <9.28g fat per 100g. The nutrient intake from LB in foods was calculated using the FNDDS. Children were classified by tertiles of LB intake. Sample‐weighted means were determined using SUDAAN. Consumption of LB contributed 3.3% to total energy, 3.9% to total fat, 3.0% to saturated fatty acids, and 12.7% to cholesterol intake. LB consumption provided a large percentage of protein (14%), vitamin B12 (21%), and zinc (19%). LB was also an important food source of other nutrients, e.g., niacin (9%), riboflavin (4%), vitamin B6 (9%), iron (6%), phosphorus (6%), potassium (6%), and magnesium (4%). LB provided <1% of total sodium intake. LB contributed positively to diets of consumers, e.g., total dietary intakes of protein, vitamins B6 & B12, zinc, iron, and potassium were higher (p<0.01), compared to non‐consumers for the top tertile of LB intake (mean 4.7 oz/d). Consumption of LB contributes significantly to intake of protein and key nutrients in diets of children. Supported by: National Cattlemen's Beef Association, and USDA.

Suppression of inositol phosphate release by cardiac myocytes isolated from fish oil-fed pigs.

Fatty acid composition of cardiac myocytes and release of inositol phosphates in pigs fed a fish oil supplemented diet was examined. Two groups of female pigs were fed diets supplemented with either 50 g/kg diet beef tallow (as control) or 50 g/kg diet fish oil (MaxEPA) rich in n-3 fatty acids. After 6 weeks of supplementation, the pigs were anesthetized and hearts were removed. Cardiac myocytes were isolated, lipid extracted and separated into non-polar and polar lipids by thin-layer chromatography. Fatty acid composition of individual neutral and polar lipid classes were examined by gas chromatography. To study the effect of membrane phospholipid modification on the phospholipase C (PLC) mediated release of inositol phosphates, cardiac myocytes were labelled with 4 microCi/mL myo-[2-(3)H]inositol for 48 h. After stimulation with epinephrine and phenylephrine, the water soluble [3H]inositol products were extracted, separated from [3H]inositol and [3H]glycerophosphoinositol by chromatography on Dowex AG 1-X8 and quantitated by scintillation counting. Cardiac myocytes isolated from fish oil-fed pigs had higher levels of n-3 polyunsaturated fatty acid in the non-esterified fatty acid and phospholipid fraction. Similarly, these cardiac myocytes had increased level of n-3 fatty and decreased n-6 fatty acids in all the phospholipid fractions, PE, PC, P1 and PS (p < 0.05). After stimulation, the levels of [3H]inositol trisphosphate (IP3) and [3H]inositol tetrakisphosphate (IP4) in cardiac myocytes isolated from fish oil-fed pigs were significantly reduced (p < 0.05) compared to myocytes isolated from beef tallow fed-pigs. This study for the first time has utilised adult cardiac myocytes to demonstrate the effect of n-3 PUFA supplementation on cardiac myocyte phospholipid fatty acid composition and release of second messengers.

Effect of High-Fat, High-Beef Diet and of Mode of Cooking of Beef in the Diet on Fecal Bacterial Enzymes and Fecal Bile Acids and Neutral Sterols

The effect of a high-fat, high-beef diet and of method of preparation of beef in the diet on the fecal bile acids and neutral sterols and on the activities of fecal bacterial beta-glucuronidase, cholesterol dehydrogenase and 7 alpha-dehydroxylase was studied in healthy men and women, 24-41 years old, who were consuming a customary mixed-western diet. The experimental diets were high in fat and beef, which was cooked rare, medium or well-done. The sequence of dietary regimen was selected at random and each diet phase lasted for 4 weeks. Individual 24-hour fecal specimens were collected from each volunteer for the final 3 days during each dietary period, including pre- and post-experimental periods while they were consuming a customary mixed-western diet. The mode of cooking beef in the high-fat, high-beef experimental diets had no influence on the fat and protein content of the diets but the fat content of experimental diets was high compared to customary mixed-western diet. Fecal bacterial beta-glucuronidase activity and fecal secondary bile acid and cholesterol metabolite levels were significantly higher during the experimental diet periods but the fecal bacterial activities of 7 alpha-dehydroxylase and cholesterol dehydrogenase were unaffected. The mode of cooking beef in experimental diets had no influence on the fecal bacterial enzymes and on the excretion of fecal bile acids and cholesterol metabolites.