Consumer acceptance of foods lower in sodium.

OBJECTIVE: To assess the magnitude of sodium reduction that can be made without significantly changing the perception of saltiness and acceptability of a broad range of common food items. DESIGN: The investigation was carried out in two phases. Military and civilian volunteers (N = 190 in study 1; N = 380 in study 2) from the US Army Natick Research, Development and Engineering Center rated the saltiness and acceptability of foods containing differing sodium concentrations. SETTING: Consumers rated food items in the sensory testing laboratory. INTERVENTION: "Regular" and "low-sodium" entrees were rated for saltiness and acceptability in study 1. Prepared food, commercially prepared food, and beverages containing various concentrations of sodium were rated for saltiness and acceptability in study 2. STATISTICAL ANALYSES PERFORMED: Results were analyzed using Pearson correlation coefficients, Student's t test, and analysis of variance. RESULTS: The perception of saltiness increased as the concentration of sodium increased. Acceptance ratings varied considerably over a broad range of sodium concentrations, which indicates that the relationship was product specific. Results suggest that a reduction of one third or more in added sodium can be made to some foods without significantly affecting consumer acceptance. APPLICATIONS: The sodium content of food can be reduced by consumer-guided food engineering and food preparation. Alterations in food preparation and product formulation, in conjunction with alterations in diet, can be effective methods for reducing sodium consumption.

Synthesis of insulin-like growth factor II (IGF-II) in fetal rat tissues: translation of IGF-II ribonucleic acid and processing of pre-pro-IGF-II.

The single insulin-like growth factor II (IGF-II) gene is transcribed into multiple RNA species in most fetal and neonatal rat tissues. For IGF-II to serve as a local growth factor in fetal tissues, IGF-II RNA must be translated into pre-pro-rat (r) IGF-II, and the biosynthetic precursor processed to smaller biologically active forms. IGF-II RNA extracted from fetal rat liver, muscle, intestine, lung, and stomach, from rat placenta, and from fetal or neonatal mouse liver and lung directed the synthesis of 22,000 mol wt pre-pro-IGF-II in a reticulocyte lysate cell-free translation system. A biosynthetic precursor of this size had been observed previously in translation of RNA from BRL-3A rat liver cells and is predicted by the nucleotide sequence of cDNA clones encoding rIGF-II. Consistent with the developmental pattern of expression of IGF-II RNA observed in hybridization studies, RNA from adult rat liver, muscle, and intestine did not direct the synthesis of pre-pro-rIGF-II. To determine whether the IGF-II biosynthetic precursor was processed to smaller biologically active IGF-II, term fetal rat tissues were extracted with acid-ethanol, the extracts were fractionated by acid gel filtration, and the IGF pools were examined in a RIA specific for IGF-II. Levels of 1-2 micrograms/g were observed in liver, limb, lung, intestine, and brain; lower levels were observed in heart and kidney. In general, the levels of immunoreactive IGF-II corresponded to the levels of IGF-II mRNA. These results suggest that IGF-II mRNA is translated, and pre-pro-IGF-II processed to mature IGF-II in different fetal rat tissues. In contrast to IGF-I, in which alternative RNA splicing generates possible precursor molecules containing different COOH-terminal propeptide segments, we find no evidence for an IGF-II precursor in rat tissues other than 22,000 mol wt pre-pro-rIGF-II.

Weight loss: a comparison of group and individual interventions.

A series of 12 behavior modification group programs (with 125 participants) was compared with 28 individual programs to determine differences in short- and long-term weight loss success. Data were collected directly and via questionnaire during the program and 10 to 36 months after the program. Different factors predicted weight loss during and after program participation, but in neither case was type of program (group vs. individual) significant. When data for the two collection periods were pooled, several factors were identified as significantly related to overall weight loss: (a) Individuals who were more overweight lost more weight. (b) The more prior programs tried the less weight loss occurred. (c) Men participating in group sessions and women seen in individual sessions lost the most weight. (d) The more sessions attended, the greater the weight loss. (e) Attending subsequent programs resulted in greater weight loss. (f) The use of behavioral technique--slow rate of eating--resulted in greater weight loss. (g) Increasing age was associated with less weight loss. The seven variables accounted for almost two-thirds (64%) of the variance.

Release of insulin-like growth factors and binding protein activity into serum-free medium of cultured human fibroblasts.

We have studied insulin-like growth factors (IGFs) and IGF-binding proteins released by human fibroblasts. Conditioned medium was obtained after incubation of 2 X 10(6) cells in 2 ml serum-free medium for 72 h. IGF binding protein was identified in aliquots of conditioned medium at 4 C for 16 h with [125]IGF II after charcoal separation. After gel filtration in neutral phosphate buffer through Sephadex G-150, the binding activity eluted with an apparent size greater than 100,000 daltons. After gel filtration through Bio-Rad P-100 in 1 M acetic acid, binding activity had a molecular size of about 50,000 daltons. When [125I]IGF-II bound to conditioned medium binding protein was cross-linked with disuccimidyl suberate and subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, the complex had an estimated molecular size of 67,000 daltons. Competitive binding studies with labeled and unlabeled IGF-I and IGF-II showed that IGF-II was preferentially bound by fibroblast binding protein. The above findings are characteristic of serum binding protein but not shed IGF surface receptors. To eliminate possible interference from binding proteins in the IGF-I RIA and the IGF-II radioreceptor assay, conditioned medium was subjected to acid gel filtration, and the peptide fractions were pooled. We found that conditioned medium of seven fibroblast lines contained 0.20 +/- 0.06 ng/ml IGF-I. After the addition of 20 ng/ml human GH (hGH), the conditioned medium contained 0.48 +/- 0.09 ng/ml. These results are lower than those previously reported. One of the two lines of fibroblasts from patients apparently resistant to GH had a minimal increase in IGF-I in conditioned medium after hGH addition. We were able to detect IGF-II in fibroblast conditioned medium in concentrations of 4.4 to 21 ng/ml but there was no consistent response to GH either in the normal fibroblast lines or in fibroblasts obtained from children with short stature.

Weight loss: long-term results in an ambulatory setting.

Maintenance of weight loss is an issue of interest to the dietetic practitioner. A series of 12 weight-loss classes was conducted using the behavioral approach. Mean weight loss of 11.1 lb. in this study compared favorably with weight losses in other studies reported in the literature. Continuous evaluation and updating of the program did not result in greater weight loss nor was it cost-effective. The participants who lost weight during the program tended to maintain weight loss over time. One-third of those participants attended additional weight-loss programs.

Receptors for insulin-like growth factors and growth effects of multiplication-stimulating activity (rat insulin-like growth factor II) in rat embryo fibroblasts.

Levels of multiplication-stimulating activity (MSA) in fetal rat serum are high (2-4 micrograms/ml), suggesting that MSA may have a role in fetal growth. We now demonstrate that fibroblasts derived from rat embryos (REFs) have specific MSA receptors and respond to MSA with increased DNA synthesis. Two types of insulin-like growth factor (IGF) receptors were demonstrated by competitive binding of radioiodinated MSA, IGF-I, and IGF-II and by chemical cross-linking of [125I]iodo-MSA and [125I]iodo-IGF-I to REFs. One type of receptor (mol wt, 260,000 under reducing conditions) did not interact with insulin, and another type of receptor (mol wt, 130,000, under reducing conditions) was recognized by insulin. Scatchard analysis of [125I]iodo-MSA binding data was consistent with one class of noninteracting binding sites. A biological response of MSA, increased DNA synthesis, was demonstrated with autoradiography in REFs. During a 16-hr incubation, DNA synthesis was stimulated by normal rat serum, and platelet-poor plasma plus platelet-derived growth factor (PDGF), but not by serum from hypophysectomized (hypox) rats or hypophysectomized (hypox) platelet-poor plasma plus PDGF. However, when MSA was added to hypox serum or to hypox platelet-poor plasma plus PDGF, DNA synthesis was stimulated to the level achieved by normal rat serum. By contrast, during a longer cell multiplication experiment, REFs grew equally well in normal or hypox rat serum, raising the possibility that REFs may produce a MSA-like factor.

Synthesis of multiplication-stimulating activity (rat insulin-like growth factor II) by rat embryo fibroblasts.

Multiplication-stimulating activity, a family of insulin-like growth factors previously identified in medium conditioned by the BRL-3A rat liver cell line, is also synthesized by third passage cultures of rat embryo fibroblasts (REFs) maintained in serum-free medium. Conditioned serum-free medium from REFs was chromatographed on Sephadex G-75 in 1 m acetic acid, and fractions in the size range of BRL-MSA contained MSA immunoreactivity. A dose-response curve of pooled G-75 fractions was parallel to BRL-MSA standard, and levels in the REF-conditioned medium were 0.5-1 microgram/ml. REF-MSA from the Sephadex G-75 pool was equipotent to BRL-MSA in stimulating [3H]thymidine incorporation into DNA in chick embryo fibroblasts and in stimulating DNA synthesis in REFs, as measured by autoradiography. In receptor binding assays using REFs, chick embryo fibroblasts, Swarm rat chondrosarcoma cells, and rat liver membranes, REF MSA was equal to BRL MSA in competition for binding of [125I]iodo-MSA. REF MSA also behaved identically to BRL MSA in a competitive binding protein assay using binding proteins in rat serum. Further characterization of REF MSA using Bio-Gel P-10 chromatography, followed by high pressure liquid chromatography or polyacrylamide gel electrophoresis, indicated that immunoreactive polypeptides in the fibroblast medium corresponded to BRL MSA II (mol wt, 8700) and BRL MSA III (mol wt, 7100). The amount of REF MSA released into the medium increased linearly over time. Cycloheximide decreased the amount of MSA in the medium, and during a recovery period, the amount of MSA returned nearly to control levels. In summary, rat embryo fibroblasts synthesize MSA which is biologically, immunologically, and chemically identical to MSA produced by the BRL-3A rat liver cell line.

The anatomy of a dietetic counseling interview.

Dietetic students in a course on interviewing skills were given an opportunity to practice interviewing, first with "coached," volunteer clients, then with real clients. Their interviews were taped and later analyzed as to content and approach. In trying to develop rapport during the "relationship-establishing" phase of the interview, the students asked questions which required mininal self-exploration by the client to answer (closed questions), five times as often as any other type of question. For effective counseling which results in changed behavior by clients, skills in counseling which develop an understanding of clients' feelings must be learned and implemented in counseling settings.

Effect of nutritional supplementation in pregnancy. II. Effect on diet.

Women judged to be at high risk of delivering low-birth-weight infants were assigned to one of three supplements--high-protein beverage, low-protein beverage, or a vitamin-mineral preparation--to determine: (a) The acceptability of a liquid dietary supplement to pregnant women. (b) The effect of the dietary supplement on diets normally eaten by pregnant women. Acceptance of the high-protein beverage by the women in this study was low. Fifty per cent of the dropouts indicated a dislike for the beverage because of either poor flavor or an inability to tolerate it. The women generally consumed "adequate" diets, although there were variations. Increases in intakes of calories and protein in Group 1 were statistically significant, suggesting the high-protein beverage served as a supplement for both calories and protein; that is, these nutrients were added to the women's existing intake. For the low-protein beverage women (Group 2), statistics revealed the beverage was used as a substitute.

Effect of nutritional supplementation in pregnancy. I. Outcome of pregnancy.

Women judged to be at high risk of delivering low-birth-weight infants were assigned to one of three supplements--high-protein beverage, low-protein beverage, or a vitamin-mineral preparation--to determine the effect these nutritional supplements would have on the outcome of pregnancy. In comparing prenatal nutrient intake and the birth weight of their infants, no significant associations were found. However, since the women were well nourished and since the sample size was small, changes in birth weight may have gone undetected. Nevertheless, a trend of increased birth weight with higher protein intake was observed.