Phosphate decreases urine calcium and increases calcium balance: A meta-analysis of the osteoporosis acid-ash diet hypothesis

<p>Abstract</p> <p>Background</p> <p>The acid-ash hypothesis posits that increased excretion of "acidic" ions derived from the diet, such as phosphate, contributes to net acidic ion excretion, urine calcium excretion, demineralization of bone, and osteoporosis. The public is advised by various media to follow an alkaline diet to lower their acidic ion intakes. The objectives of this meta-analysis were to quantify the contribution of phosphate to bone loss in healthy adult subjects; specifically, a) to assess the effect of supplemental dietary phosphate on urine calcium, calcium balance, and markers of bone metabolism; and to assess whether these affects are altered by the b) level of calcium intake, c) the degree of protonation of the phosphate.</p> <p>Methods</p> <p>Literature was identified through computerized searches regarding phosphate with surrogate and/or direct markers of bone health, and was assessed for methodological quality. Multiple linear regression analyses, weighted for sample size, were used to combine the study results. Tests of interaction included stratification by calcium intake and degree of protonation of the phosphate supplement.</p> <p>Results</p> <p>Twelve studies including 30 intervention arms manipulated 269 subjects' phosphate intakes. Three studies reported net acid excretion. All of the meta-analyses demonstrated significant decreases in urine calcium excretion in response to phosphate supplements whether the calcium intake was high or low, regardless of the degree of protonation of the phosphate supplement. None of the meta-analyses revealed lower calcium balance in response to increased phosphate intakes, whether the calcium intake was high or low, or the composition of the phosphate supplement.</p> <p>Conclusion</p> <p>All of the findings from this meta-analysis were contrary to the acid ash hypothesis. Higher phosphate intakes were associated with decreased urine calcium and increased calcium retention. This meta-analysis did not find evidence that phosphate intake contributes to demineralization of bone or to bone calcium excretion in the urine. Dietary advice that dairy products, meats, and grains are detrimental to bone health due to "acidic" phosphate content needs reassessment. There is no evidence that higher phosphate intakes are detrimental to bone health.</p

Etiquetado y rotulación de los alimentos en la prevención del sobrepeso y la obesidad: una revisión sistemática Food labeling and the prevention of overweight and obesity: a systematic review

Revisión de los artículos sobre el etiquetado o la rotulación en la prevención de la obesidad y el sobrepeso. Estudio, mediante técnica sistemática, de los trabajos recuperados mediante revisión bibliográfica. Bases de datos consultadas: MEDLINE, EMBASE, Web of Knowledge, Cochrane Library Plus, Food Science and Technology Abstracts, LILACS y CINAHL. Descriptores DeCS/MeSH: obesity y food labeling. 207 artículos recuperados, mediante los criterios de inclusión y exclusión, se seleccionaron 14: 11 sobre etiquetado y la rotulación en el consumo final del producto; 2 sobre establecimientos de comida rápida. Uno sobre atributos sensoriales en contraste con recomendaciones saludables y 2 realizaron un seguimiento de las intervenciones. El etiquetado y la rotulación tienen efecto positivo en el consumo final de los alimentos, suceso no observado en restaurantes de comida rápida. Los atributos sensoriales fueron más efectivos que las recomendaciones recogidas en el etiquetado. El seguimiento de las actuaciones confirmó el efecto a largo plazo de las intervenciones estudiadas.<br>This article reports on a systematic review of articles on food labeling and the prevention of obesity and overweight, in the MEDLINE, EMBASE, Web of Knowledge, Cochrane Library Plus, Food Science and Technology Abstracts, LILACS, and CINAHL databases. The DeCS/MeSH descriptors were obesity and food labeling. 207 articles were retrieved. Using inclusion and exclusion criteria, 14 articles were selected: 11 were on food labeling and its impact on final food product consumption; 2 were on fast food establishments; 1 on sensory attributes as compared to health recommendations; and 2 on follow-up of interventions. Labeling has a positive effect on final food product consumption, in contrast with fast food restaurants. Sensory attributes were more effective than recommendations on the labels. Follow-up of interventions confirmed the long-term effect of the target interventions

Risk factors for childhood overweight in 6- to 7-y-old Hong Kong children

OBJECTIVE: To identify risk factors for overweight in Hong Kong children aged 6-7 y. DESIGN: Case-control study. SETTING: Student Health Service Centres, Hong Kong. SUBJECTS: A total of 343 Hong Kong Chinese children aged 6-7 y old categorised into three groups, an overweight group (≥ 92nd centile for BMI), a normal middle-weight group (45th-55th centile for BMI) and a normal low-weight group (≤ 8th centile for BMI). MEASUREMENTS: Subjects and their parents/caregivers were interviewed at home. Data on lifestyle habits, dietary habits, family structure and demographic background were collected by questionnaire. A 3-day dietary record was administrated by the parents/caregivers to assess dietary intake of the children. RESULTS: Logistic regression analyses (overweight group compared with middle-weight plus low-weight groups) showed that childhood overweight was significantly associated with parental obesity (BMI ≥ 25 kg/m2, Asian reference) (paternal: OR = 2.66, 95% CI = 1.51-4.70; maternal: 5.07, 2.62-9.79) but not parental overweight (BMI = 23-25 kg/m2). After adjustment for parental obesity, the odds ratio for childhood overweight was increased by birth weight (< 3.0 kg as reference, 3.0-3.5 kg: 2.13, 1.18-3.84; ≥ 3.5 kg: 4.89, 2.49-9.60) and decreased by sleeping duration (< 9 h/day as reference, 9-11 h/day: 0.54, 0.30-0.97; ≥ 11 h/day: 0.31, 0.11-0.87). Childhood overweight was also significantly associated with higher energy consumption (2.62, 1.20-5.74) and having a father who was a current smoker (2.08, 1.25-3.46). CONCLUSIONS: Although healthy diet and regular exercise will remain the cornerstones of obesity management in children, our data support the view that education about maintaining a healthy weight could be introduced much earlier in those families with high-risk children, as indicated by high parental BMI or high birth weight. The utility and practicality of such an approach should be carefully evaluated before becoming part of any public health policy. Further study of the role of short sleeping duration and parental smoking on childhood obesity development is warranted.link_to_subscribed_fulltex