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Development and content validity of an instrument for assessing the motivation for weight loss in adolescents with overweight and obesity.
Silva, DFO, Souza, ALS, Pimentel, JB, Souza, TO, Araújo, EPDS, Sena-Evangelista, KCM, Arrais, RF, Lima, SCVC
PloS one. 2020;15(11):e0242680
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Reduction and control of body weight is an important measure in order to reduce health risks in adolescence and adulthood. The aim of this study was to develop and validate the content of an instrument to assess the motivation for weight loss in adolescents with overweight and obesity. This is a methodological study. The development and content validation of the instrument was conducted in five stages. There were three rounds of evaluation; in the first round the responses of 12 experts were included, in the second round the responses of 10 experts were included and in the final round the responses of four experts were included. Findings show that the content validity evaluation of the items by the panel of experts allowed the selection of the most practical items for adolescents. Additionally, the revisions made in the wording of the items provided a better standardization in the presentation of the items and a clearer language adapted to the age range of the target audience. Authors conclude that further psychometric testing is needed to determine reliability and construct validity of the instrument.
Abstract
OBJECTIVE To develop and validate the content of an instrument for assessing the motivation for weight loss in adolescents with overweight and obesity. METHODS The development and validation of the instrument were conducted in five stages, for which two systematic reviews were conducted. The first one, for the identification of questionnaires assessing the motivation for weight loss, included six studies and contributed to the selection of the domains for the instrument. The second one, conducted to identify the motivations for weight loss in adolescents with overweight and/or obesity, included six studies and contributed to the selection of 17 motivations included in the initial version of the instrument. The motivations most commonly identified were: having better health, improving my appearance, improving my self-esteem and avoiding bullying. The content validity was confirmed by a committee of 12 experts from the areas of nutrition, endocrinology, psychology, and physical education. Based on these evaluations, the content validity index was calculated. Only the items with a content validity index >0.80 for practical relevance were held in the instrument. RESULTS Five of the 17 motivations included in the initial version of the instrument were excluded because they had content validity index <0.80 for practical relevance. Of the 12 items held in the instrument, five were revised by experts in order to standardize wording and make the language more appropriate for adolescents. Experts categorized the items into the health, personal satisfaction, appearance and social domains. CONCLUSIONS This is the first instrument assessing the motivation for weight loss in adolescents with overweight and obesity in Brazil. The content validity evaluation by the panel of experts provided more practical relevance, as well as contributed to a better presentation of the items. Further psychometric testing is needed to determine reliability and construct validity of the instrument.
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Hormonal and psychobehavioral predictors of weight loss in response to a short-term weight reduction program in obese women.
Hainer, V, Hlavatá, K, Gojová, M, Kunešová, M, Wagenknecht, M, Kopský, V, Pařízková, J, Hill, M, Nedvídková, J
Physiological research. 2008;57 Suppl 1:S17-S27
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Among the many factors that influence weight loss and weight management, metabolic and hormonal parameters have been increasingly explored as important predictors. The aim of this study was to reveal potential psycho-behavioural and hormonal factors as predictors of weight loss. A group of 67 overweight women were enrolled in a 3-week weight management programme in which food intake and physical activity were under strict control. This study indicated that a short-term weight management programme induced favourable changes in anthropometric, psycho-behavioural and hormonal indices. Changes in several hormone concentrations were significantly associated with the reduction of anthropometric parameters, however psycho-behavioural factors did not contribute to weight change in the programme.
Abstract
Among the factors influencing weight loss and maintenance, psychobehavioral, nutritional, metabolic, hormonal and hereditary predictors play an important role. Psychobehavioral factors influence adherence to lifestyle changes and thus weight loss maintenance. The outcome of short-term weight reduction treatment is mainly affected by changes in energy and nutrient intake and physical activity and thus the impact of hormones can possibly be obscured. In order to reveal hormonal determinants of weight loss, a 4-week in-patient comprehensive weight reduction program was introduced in which food intake and physical activity were under the strict control. Women (n = 67, BMI: 32.4+/-4.4 kg; age: 48.7+/-12.2 years) who exhibited stable weight on a 7 MJ/day diet during the first week of weight management were given a hypocaloric diet yielding daily energy deficit 2.5 MJ over the subsequent 3-week period. This treatment resulted in a mean weight loss of 3.80+/-1.64 kg. Correlation analysis revealed that baseline concentrations of several hormones were significantly associated either with a higher (free triiodothyronine, C-peptide, growth hormone, pancreatic polypeptide) or with a lower (insulin-like growth factor-I, cortisol, adiponectin, neuropeptide Y) reduction of anthropometric parameters in response to weight management. In a backward stepwise regression model age, initial BMI together with baseline levels of growth hormone, peptide YY, neuropetide Y and C-reactive protein predicted 49.8 % of the variability in weight loss. Psychobehavioral factors (items of the Eating Inventory, Beck Depression score) did not contribute to weight change induced by a well-controlled short-term weight reduction program.
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Plasma ghrelin concentrations are lower in binge-eating disorder.
Geliebter, A, Gluck, ME, Hashim, SA
The Journal of nutrition. 2005;135(5):1326-30
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Binge Eating Disorder (BED) is characterised by eating a large quantity of food (objectively) at least 2 times a week for 6 months, and is associated with a loss of feelings of self control. It is found it around 30% of obese individual who participate in weight loss programs. There may be a biological element to this disorder with possible mechanisms including heritability, an enlarged stomach capacity and genetic mutations. Hormones may also play a role in BED. This study aimed to establish whether obese individuals had higher fasting and post feeding ghrelin levels, and slower gastric emptying compared to a non-obese BED control group. 38 overweight and obese women were recruited and classified into one of three groups; non binge eaters (12), binge eaters but not meeting full BED criteria (14) and BED syndrome (11). 10 of the 11 BED women were randomly allocated to a 6 week treatment of either a) cognitive behavioural therapy (CBT) and a diet or b) a non treatment wait-list control. The study found that the BED women had a lower fasting ghrelin level and that ghrelin also declined less after a meal for this group. The authors stated that this appeared to be counterintuitive because ghrelin (which stimulates hunger) was expected to be higher for overweight and obese people. They suggest that binge eating may down-regulate ghrelin and be a response to over-eating (often when not hungry). They also suggested that ghrelin declining less for overweight and obese BED women may suggest that the magnitude of the ghrelin fall may be linked to higher satiation (so they have lower satiation and continue eating compared to other individuals).
Abstract
Binge-eating disorder (BED), characterized by binge meals without purging afterward, is found in about 30% of obese individuals seeking treatment. The study objective was to ascertain abnormalities in hormones influencing appetite in BED, especially ghrelin, an appetite-stimulating peptide, which was expected to be elevated. Measurements were made of plasma insulin, leptin, glucagon, cholecystokinin, and ghrelin, as well as glucose following an overnight 12-h fast, prior to and after ingestion (from 0 to 5 min) of a nutritionally complete liquid meal (1254 kJ) at 0830 h, at -15, 0, 5, 15, 30, 60, 90, and 120 min. Appetite ratings including hunger and fullness were also obtained. An acetaminophen tracer was used to assess gastric emptying rate. Three groups of comparably obese women (BMI = 35.9 +/- 5.5; % body fat = 44.9 +/- 4.7) participated: 12 nonbinge eating normals (NB), 14 subthreshold BED, and 11 BED. The BED subjects, compared to NB subjects, had lower baseline ghrelin concentrations prior to the meal, a lower area under the curve (AUC), with lower levels at 5, 15, 30, 90, and 120 min, and a smaller decline in ghrelin postmeal (all P < 0.03). The other blood values did not differ among groups, and neither did gastric emptying rate nor ratings of fullness. The BED subjects were then randomly assigned to treatment with cognitive-behavior therapy and diet (n = 5) or to a wait-list control (n = 4). Baseline ghrelin (P = 0.01) and AUC increased (P = 0.02), across both conditions, in which most subjects (7 of 9) stopped binge eating. The lower fasting and postmeal plasma ghrelin levels in BED are consistent with lower ghrelin levels in obese compared to lean individuals and suggests downregulation by binge eating.
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Lysine fortification reduces anxiety and lessens stress in family members in economically weak communities in Northwest Syria.
Smriga, M, Ghosh, S, Mouneimne, Y, Pellett, PL, Scrimshaw, NS
Proceedings of the National Academy of Sciences of the United States of America. 2004;101(22):8285-8
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The risk of protein deficiency, particularly lysine, is high among communities that depend on wheat for their protein supply. In experimental animals, prolonged lysine inadequacy increases stress-induced anxiety, however the evidence of nutritional benefits for fortifying wheat with lysine is limited. The aim of this study was to investigate whether consuming lysine-fortified wheat for three months would reduce stress and anxiety in Northwest Syrian rural communities. This study indicated that lysine fortification significantly reduced anxiety in males. These results suggest that some stress responses among economically weak populations consuming wheat-based diets can be improved with lysine fortification.
Abstract
Lysine is a limiting amino acid in diets based on wheat as the staple. In experimental animals, prolonged dietary lysine inadequacy increases stress-induced anxiety. If observed in humans, such a result would have a strong implication for the relationship between nutrition and communal quality of life and mental health. As part of a 3-month randomized double-blind study, we tested whether lysine fortification of wheat reduces anxiety and stress response in family members in poor Syrian communities consuming wheat as a staple food. In the lysine-fortified group, the plasma cortisol response to the blood drawing as a cause of stress was reduced in females, as was sympathetic arousal in males as measured by skin conductance. Lysine fortification also significantly reduced chronic anxiety as measured by the trait anxiety inventory in males. These results suggest that some stress responses in economically weak populations consuming cereal-based diets can be improved with lysine fortification.