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Biomedical subjects

E Saltzman

Publications and source records attributed to E Saltzman.

At least 19 recordsLinked to original sources

Binge eating disorder in extreme obesity.

OBJECTIVE: To determine whether extremely obese binge eating disorder (BED) subjects (BED defined by the Eating Disorder Examination) differ from their extremely obese non-BED counterparts in terms of their eating disturbances, psychiatric morbidity and health status. DESIGN: Prospective clinical comparison of BED and non-BED subjects undergoing gastric bypass surgery (GBP). SUBJECTS: Thirty seven extremely obese (defined as BMI > or = 40 kg/m(2)) subjects (31 women, six men), aged 22-58 y. MEASUREMENTS: Eating Disorder Examination 12th Edition (EDE), Three Factor Eating Questionnaire (TFEQ), Structured Clinical Interview for the Diagnostic and Statistical Manual-IV (SCID-IV), Short-Form Health Status Survey (SF-36), and 24 h Feeding Paradigm. RESULTS: Twenty-five percent of subjects were classified as BED (11% met full and 14% partial BED criteria) and 75% of subjects were classified as non-BED. BED (full and partial) subjects had higher eating disturbance in terms of eating concern and shape concern (as found by the EDE), higher disinhibition (as found by the TFEQ), and they consumed more liquid meal during the 24 h feeding paradigm. No difference was found in psychiatric morbidity between BED and non-BED in terms of DSM-IV Axis I diagnosis. The health status scores of both BED and non-BED subjects were significantly lower than US norms on all subscales of the SF-36, particularly the BED group. CONCLUSION: Our findings support the validity of the category of BED within a population of extremely obese individuals before undergoing GBP. BED subjects differed from their non-BED counterparts in that they had a greater disturbance in eating attitudes and behavior, a poorer physical and mental health status, and a suggestion of impaired hunger/satiety control. However, in this population of extremely obese subjects, the stability of BED warrants further study.

Adult↗

A dynamical model of locomotion in spastic hemiplegic cerebral palsy: influence of walking speed.

OBJECTIVE: The objective of this study was to assess the capability of an escapement-driven inverted pendulum with springs and damping model to estimate the effects of impairments (e.g. spasticity, muscle weakness) on the dynamics and patterns of locomotion of children with spastic cerebral palsy. METHODS: Kinematic data of six children with spastic hemiplegic cerebral palsy and six matched, typically developing children were collected at five different self-selected overground walking speeds ('very slow' to 'very fast'). Changes in forcing, stiffness and gravitational potentials were estimated during the stance phase of each leg according to the model's equation of motion. RESULTS: Significantly greater stiffness and decreased forcing was observed in the more affected limbs of children with spastic hemiplegic cerebral palsy and compared to typically developing peers. The forcing term of the non-affected limb was greater than that of the matched typically developing children. CONCLUSIONS: Results support the claim that disabled individuals with losses in dynamic resources (stiffness, muscle forcing capability) exploit and develop the remaining resources in their adapted gait patterns. It was suggested that clinical interventions aimed at normalizing a gait pattern may be contraindicated, and that rehabilitation might be more effective if focused at the level of dynamics. RELEVANCE: Pattern formation is seen as an optimal solution based on the individuals' action capabilities and dynamic properties under environmental and task demands. This perspective could lead to the development of interventions that address these dynamic variables with the objective of improving the functional capabilities of children with cerebral palsy.

Adolescent↗

Effects of a cereal rich in soluble fiber on body composition and dietary compliance during consumption of a hypocaloric diet.

OBJECTIVES: To investigate the effects of oats, a cereal rich in soluble fiber, on body composition changes and dietary compliance during consumption of a weight loss diet. METHODS: Subjects were 41 healthy men and women aged 18 to 78 years. Weight maintenance energy requirements were established over two weeks during consumption of a control diet with low soluble fiber content. Subjects then consumed a hypocaloric diet for six weeks, either consuming a low soluble fiber control diet or a diet containing 45 g/1000 kcal rolled oats, a whole grain cereal rich in soluble fiber (mean energy deficit -895+/-18 kcal/day relative to weight maintenance energy requirements). Changes in body fat and fat-free mass were determined by underwater weighing, and dietary compliance was assessed using the urinary osmolar excretion rate technique. In a final phase of the study, subjects ate ad libitum for six months, and changes in body weight and composition were monitored. RESULTS: There was no significant effect of the oat-containing diet on body weight or composition changes during the hypocaloric regimen or in the subsequent ad libitum period. In addition, fecal energy excretion was not significantly different between groups. However, there were non-significant trends indicating reduced hunger in the oat group compared to controls (frequency of hunger 2.5+/-0.5 vs. 3.6+/-0.4, P=0.1). In addition, fewer oat subjects were non-compliant (four versus seven subjects dropped out or had urinary osmolar excretions greater than 130% of values predicted from dietary intake), but again the difference was not significant. CONCLUSIONS: These results suggest that use of a cereal rich in soluble fiber in a closely monitored hypocaloric feeding regimen does not improve weight loss or dietary compliance. Further studies are needed to examine the possibility that cereals containing soluble fiber may have effects on hunger and dietary compliance that could be important in less tightly controlled protocols than the one described here.

Adult↗

Effects of a hydrogenated form of vitamin K on bone formation and resorption.

BACKGROUND: Hydrogenation of vegetable oils affects blood lipid and lipoprotein concentrations. However, little is known about the effects of hydrogenation on other components, such as vitamin K. Low phylloquinone (vitamin K1) intake is a potential risk factor for bone fracture, although the mechanisms of this are unknown. OBJECTIVE: The objective was to compare the biological effects of phylloquinone and its hydrogenated form, dihydrophylloquinone, on vitamin K status and markers of bone formation and resorption. DESIGN: In a randomized crossover study in a metabolic unit, 15 young adults were fed a phylloquinone-restricted diet (10 microg/d) for 15 d followed by 10 d of repletion (200 microg/d) with either phylloquinone or dihydrophylloquinone. RESULTS: There was an increase and subsequent decrease in measures of bone formation (P = 0.002) and resorption (P = 0.08) after dietary phylloquinone restriction and repletion, respectively. In comparison with phylloquinone, dihydrophylloquinone was less absorbed and had no measurable biological effect on measures of bone formation and resorption. CONCLUSION: Hydrogenation of plant oils appears to decrease the absorption and biological effect of vitamin K in bone.

Adult↗

An oat-containing hypocaloric diet reduces systolic blood pressure and improves lipid profile beyond effects of weight loss in men and women.

Hypertension, dyslipidemia and overweight contribute substantially to cardiovascular disease risk. One of the most effective methods for improving high blood pressure and lipid profiles is loss of excess weight. Other recommendations for reducing cardiovascular risk include changes in dietary micronutrient, macronutrient and fiber intakes. To better define a diet for reduction in cardiovascular risk, 43 adults (body mass index 26.4 +/- 3.3, range 20.5-33.9 kg/m(2)) participated in an 8-wk study to determine the effects of two diets on weight, blood pressure, lipids and insulin sensitivity. For 2 wk, weight was maintained and all subjects consumed a control diet. For the next 6 wk, subjects consumed one of two hypocaloric diets (maintenance energy minus 4.2 MJ/d): the control diet (n = 21) or a diet containing oats [45 g/(4.2 MJ dietary energy. d), n = 22]. There was no significant difference between groups in changes in weight loss (control -4.0 +/- 1.1 kg, oats -3.9 +/- 1.6 kg, P = 0.8). The oats diet resulted in greater decreases in mean systolic blood pressure (oats -6 +/- 7 mm Hg, control -1 +/- 10 mm Hg, P = 0.026), whereas diastolic blood pressure change did not differ between the two groups (oats -4 +/- 6 mm Hg, control -3 +/- 5 mm Hg, P = 0.8). The oat diet resulted in significantly greater decreases in total cholesterol (oats -0.87 +/- 0.47 mmol/L, control -0.34 +/- 0.5 mmol/L, P = 0.003) and LDL cholesterol (oats -0.6 +/- 0.41 mmol/L, control -0.2 +/- 0.41mmol/L, P = 0.008). In summary, a hypocaloric diet containing oats consumed over 6 wk resulted in greater improvements in systolic blood pressure and lipid profile than did a hypocaloric diet without oats.

Adult↗

An underfeeding study in healthy men and women provides further evidence of impaired regulation of energy expenditure in old age.

The effect of aging on energy regulation remains controversial. We compared the effects of underfeeding on changes in energy expenditure and respiratory quotient in young normal weight men and women [YNW, age 25.7 +/- 3.2 y(SD), body mass index (BMI) 23.1 +/- 1.6 kg/m(2)], young overweight men and women (YOW, age 26.1 +/- 3.5 y, BMI 27.7 +/- 2.1 kg/m(2)) and older (OLD) men and women (age 68.4 +/- 3.3 y, BMI 27.4 +/- 3.4 kg/m(2)). The thermic effect of feeding (TEF) during weight maintenance, and changes in resting energy expenditure (REE) and respiratory quotient were determined in response to undereating by an average 3.75 MJ/d for 6 wk. In addition, body composition was measured. No significant differences among the groups were observed in TEF, fasting and postprandial respiratory quotient, or the change in fasting respiratory quotient with underfeeding. However, REE adjusted for fat-free mass and fat mass was significantly lower in OLD subjects compared with YNW and YOW subjects (P < 0.05). In addition, the REE response to weight change was significantly attenuated in the OLD subjects (P = 0.023). These data suggest that the responsiveness of energy expenditure to negative energy balance is attenuated in old age, and provide further support for the hypothesis that mechanisms of energy regulation are broadly disregulated in old age.

Adult↗

Dietary fiber and weight regulation.

The influence of dietary fiber on energy regulation remains controversial. This review summarizes published studies on the effects of dietary fiber on hunger, satiety, energy intake, and body composition in healthy individuals. Under conditions of fixed energy intake, the majority of studies indicate that an increase in either soluble or insoluble fiber intake increases postmeal satiety and decreases subsequent hunger. When energy intake is ad libitum, mean values for published studies indicate that consumption of an additional 14 g/day fiber for >2 days is associated with a 10% decrease in energy intake and body weight loss of 1.9 kg over 3.8 months. Furthermore, obese individuals may exhibit a greater suppression of energy intake and body weight loss (mean energy intake in all studies was reduced to 82% by higher fiber intake in overweight/obese people versus 94% in lean people; body weight loss was 2.4 kg versus 0.8 kg). These amounts are very similar to the mean changes in energy intake and body weight changes observed when dietary fat content is lowered from 38% to 24% of energy intake in controlled studies of nonobese and obese subjects. The observed changes in energy intake and body weight occur both when the fiber is from naturally high-fiber foods and when it is from a fiber supplement. In view of the fact that mean dietary fiber intake in the United States is currently only 15 g/day (i.e., approximately half the American Heart Association recommendation of 25-30 g/day), efforts to increase dietary fiber in individuals consuming <25 g/day may help to decrease the currently high national prevalence of obesity.

Body Composition↗

Effects of a 6-week hypocaloric diet on changes in body composition, hunger, and subsequent weight regain in healthy young and older adults.

Recent studies have suggested a short-term impairment in the regulation of food intake in older adults, but further studies are needed to determine if a longer-term impairment exists and to identify underlying causes. Changes in body weight and composition were measured over a 6-week underfeeding study and a 6-month follow-up period in healthy young (n = 23) and older (OLD, n = 18) men and women. The young adults were either normal weight (YNW, n = 12) or overweight (YOW, n = 11). Energy intakes during underfeeding were 896 +/- 18 (SEM) kcal less than weight-maintenance energy requirements determined prior to underfeeding. In addition, changes in perceived hunger during underfeeding were monitored in a subgroup (n = 19). OLD and YOW subjects lost significantly more weight during underfeeding than did YNW subjects (p = .025 and .000, respectively), and they did not gain back significant weight in the 6-month follow-up. In addition, OLD subjects reported a significantly lower frequency of hunger during underfeeding (p = .05). There was no significant difference among groups in the relationship between weight lost and fat-free mass lost. Healthy OLD adults have an impaired ability to regulate food intake over at least 6 months following underfeeding compared with YNW adults, and a reduction in their perceived frequency of hunger may be a contributing factor.

Adult↗

Dietary determinants of energy intake and weight regulation in healthy adults.

Until recently, the percentage of energy from dietary fat has been considered a primary determinant of body fatness. This review covers recent studies from our laboratory that challenge this notion. High and low fat diets matched for energy density, palatability and fiber resulted in similar mean voluntary energy intakes over 9 d; analysis of the individual foods in these diets showed that energy density and palatability were significant determinants of energy intake, independent of fat content. Path analysis further revealed that the influence of energy density on energy intake was in part direct, and in part indirect and mediated by palatability. In another study, dietary variety within food groups was shown to be an important predictor of body fatness, and the direction of the association depended on which food groups provided the variety, i.e., the variety of sweets, snacks, condiments, entrees and carbohydrates consumed was positively associated with body fatness, whereas the variety of vegetables was negatively associated. Last, a study of restaurant food and body fatness showed that the frequency of consumption of restaurant food was positively associated with body fatness, independent of education level, smoking status, alcohol intake and physical activity. Restaurant meals tend to be high in fat and low in fiber, and thus energy dense. Restaurants also typically serve a variety of palatable foods in large portions. The increasing variety of high energy foods available and the increasing proportion of household income spent on foods consumed away from home may help explain the U.S. national rising prevalence of obesity.

Adult↗

Dynamics of intergestural timing: a perturbation study of lip-larynx coordination.

In this study, downward-directed mechanical perturbations were applied to the lower lip during both repetitive (/...paepaepae.../) and discrete (/pe'saepaepl/) utterances in order to examine the perturbation-induced changes of intergestural timing between syllables (i.e., between the bilabial and laryngeal gestures for successive /p/'s) and within phonemes (i.e., between the bilabial and laryngeal gestures within single /p/'s). Our findings led us to several conclusions. First, steady-state (phase-resetting) analyses of the repetitive utterances indicated both that "permanent" phase shifts existed for both the lips and the larynx after the system returned to its pre-perturbation rhythm and that smaller steady-state shifts occurred in the relative phasing of these gestures. These results support the hypothesis that central intergestural dynamics can be reset by peripheral articulatory events. Such resetting was strongest when the perturbation was delivered within a "sensitive phase" of the cycle, during which the downwardly directed lower-lip perturbation opposed the just-initiated, actively controlled bilabial closing gesture for /p/. Although changes in syllable duration were found for other perturbed phases, these changes were simply transient effects and did not indicate a resetting of the central "clock." Second, analyses of the transient portions of the perturbed cycles of the repetitive utterances indicated that the perturbation-induced steady-state phase shifts are almost totally attributable to changes occurring during the first two perturbed cycles. Finally, the transient changes in speech timing induced by perturbations in the discrete sequences appeared to share a common dynamical basis with the changes to the repetitive sequences. We conclude by speculating on the type of dynamical system that could generate these temporal patterns.

Adult↗

The effects of age on postprandial thermogenesis at four graded energetic challenges: findings in young and older women.

There remains controversy over the effect of age on postprandial thermogenesis, with some studies observing decreased postprandial thermogenesis in older subjects and other studies finding no effect of age. We investigated this issue in 8 young (25.2+/-1.8 years) and 8 older (72.2+/-2.1 years) healthy glucose-tolerant women with normal thyroid hormone status. Repeated measures of the thermic effect of feeding (TEF) were obtained following consumption of test meals containing 0, 1046, 2092, and 4184 kilojoules (kJ) by using indirect calorimetry. TEF at each meal size was determined once in the older subjects and twice in the younger subjects (during follicular and luteal phases of the menstrual cycle) for a total of 96 measurements. There was a positive dose-response between meal size and TEF (p < .001) that was not significantly affected by age group. The best single predictor of TEF expressed as a percentage of meal energy content was waist-to-hip ratio (R2=67.416, p < .02). These results indicate that aging is not associated with decreased TEF in the absence of factors such as a hypothyroid state or glucose intolerance.

Adult↗

Soluble fiber and energy regulation. Current knowledge and future directions.

Soluble dietary fiber is a potentially important factor determining our ability to maintain a stable energy balance and avoid obesity. However, clinical metabolic investigations have given conflicting results on the effects of soluble fiber on energy regulation, perhaps for the reasons that a) other dietary components that affect energy regulation have not always be controlled adequately and b) in the past it has been hard to ensure that subjects are consistently compliant with the dietary requirements of soluble fiber protocols. The recent development of techniques for assessing dietary compliance in metabolic studies, combined with increased control of non-fiber dietary variables that influence energy intake, should help ensure more consistent findings in future investigations.

Adolescent↗

Fat oxidation in response to four graded energy challenges in younger and older women.

We examined whether older individuals have an impairment in their ability to oxidize dietary fat, a factor that could help to explain age-associated weight gain. The subjects were 16 healthy younger and older women. Fat oxidation was determined by indirect calorimetry before and after consumption of four different test meals consumed > or = 5 d apart. The intervention meals contained 0, 1046, 2092, or 4184 kJ (simulating extended fasting, and consumption of a snack, a small meal, and a moderately large meal, respectively), with 35% of energy from fat. The duration of each measurement was the amount of time required for postprandial energy expenditure to return to the premeal fasting value. A total of 96 measurements were obtained, including duplicates for all meal sizes in the younger women (in the follicular and luteal phases of the menstrual cycle). Total postprandial fat oxidation increased in proportion to meal size in the younger subjects, but did not increase above that for the 2092-kJ meal in the older women. In addition, older subjects had significantly lower total fat oxidation after consumption of the 4184-kJ meal (781 compared with 1029 kJ/measurement, P < 0.02) and also significantly greater fat deposition (745 compared with 464 kJ/measurement, P < 0.02). These findings suggest that, relative to younger women, older women have a reduced ability to oxidize dietary fat when they consume large meals.

Adult↗

Effect of high-fat and low-fat diets on voluntary energy intake and substrate oxidation: studies in identical twins consuming diets matched for energy density, fiber, and palatability.

There remains controversy over the effects of dietary fat content on voluntary energy intake. Additionally, the question of whether there is a genetic susceptibility to overeating high-fat diets has not been resolved. To address these issues, we designed two diets: a low-fat diet providing approximately 20% of energy as fat and a high-fat diet with approximately 40% of energy as fat. The diets were matched for energy density, fiber, and palatability. In a two-phase, 18-d intervention study, voluntary energy intakes and macronutrient oxidation rates during the fasting and fed states were determined in seven pairs of identical male twins. In contrast with results of previous intervention studies, in which low-fat and high-fat diets were not matched for energy density and other associated variables, we observed no significant difference in voluntary energy intake between the low-fat and high-fat phases, and mean daily intakes were similar (10.3 and 10.7 MJ/d, respectively). Postprandial rates of fat oxidation tended to reflect fat intakes in the two dietary phases, thus helping to explain the lack of a difference in mean energy intakes. There was also a significant twin-pair similarity in differences in energy intakes between dietary phases (P = 0.013). These results suggest that dietary fat content does not have a major influence on voluntary energy intake when dietary variables usually associated with fat are controlled for and that there may be a familial influence on the effects of dietary fat content on energy intake.

Adult↗