Meal replacements are as effective as medications for weight maintenance

In a recent study published in the Journal of the American College of Nutrition, the effectiveness of meal replacements in weight loss maintenance was examined.

Participants followed a liquid very low calorie diet (VLCD) for 12 weeks followed by 4 weeks of re-orientation to solid food. At week 16, the subjects were randomly selected to receive either meal replacements or Orlistat, both combined with a structured meal plan calculated to maintain weight loss. For one year, all subjects followed a weight management program that included topics such as lifestyle, physical activity and nutrition.

During the VLCD, the meal replacement group lost an average of 50.2 lbs and the Orlistat group lost an average of 49 lbs. During weight maintenance, there were no significant differences in physical activity, fruit and vegetable intake and pedometer steps between the groups. After one year, the meal replacement group had regained 5.9 lbs and the Orlistat group had regained 6.2 lbs.

Meal replacements and Orlistat were both effective in maintaining weight significantly below baseline levels over a year period of time. Meal replacements, therefore, may be a viable alternative to medications for weight maintenance.

Journal of the American College of Nutrition, Vol. 24, No. 5, 347-353 (2005)

Vitamin D levels linked to healthy lung function

Researchers in New Zealand recently examined the relationship between lung function and vitamin D and published their findings in the December issue of the journal Chest. Low concentrations of vitamin D have been associated with a number of diseases, including osteoporosis, hypertension, and type I diabetes. Research now indicates that serum concentrations of vitamin D might also influence pulmonary function.

Subjects included 14,091 adults, participants from the US National Health and Nutrition Examination Survey (NHANES III) carried out between 1988 and 1994. Lung function was measured by the volume of air that could be forcibly blown out in total, the forced vital capacity (FVC), or in one second, the forced expiratory volume (FEV1). Vitamin D was measured using serum 25-hydroxyvitamin D, the standard indicator of vitamin D levels.

The difference in lung function between the groups with the highest and lowest vitamin D intake was substantial in both the FVC and FEV1 tests.

Although further studies are necessary to determine whether supplementation with vitamin D is of any benefit in patients with chronic respiratory disease, the researchers stated that vitamin D supplements could be a simple, low-cost method to prevent or slow the loss of lung function.

Chest 2005 Dec;128(6):3792-8.

Magnesium intake may reduce the risk of osteoporosis

A recent study published in the Journal of the American Geriatric Society has shown that dietary intake of magnesium is associated with an increase in bone mineral density in older men and women.

The study included 2,038 men and women aged 70-79 that were enrolled in the Health, Aging and Body Composition Study. Food frequency questionnaires were used to assess magnesium intakes and document any medications. The data also accounted for variations in age, body mass index (BMI), smoking status, alcohol use, physical activity, estrogen use, and supplemental calcium and vitamin D.

Higher Mg intake through diet and supplements was positively associated with total - body bone mineral density (BMD) in older white men and women. For every 100 mg per day increase in Mg, there was an approximate 2 per cent increase in whole-body BMD. The results have important implications since osteoporosis currently affects over 10 million adults in the U.S. alone, with another 34 million suspected to have low bone mass. In addition, earlier dietary surveys have consistently shown that a large portion of adults do not meet the RDA for magnesium.

Journal of the American Geriatrics Society November, Vol 53, No 11, pp 1875-1880

Fiber intake associated with reduced cardiovascular disease risk factors

Increased dietary fiber intake is associated with reduced levels of a number of cardiovascular disease risk factors. The results of a study published in the December 2005 issue of the American Journal of Clinical Nutrition adds to a growing body of evidence linking higher dietary fiber intake with a lower risk of heart disease.

Nearly 6,000 men and women were selected from participants in an ongoing trial designed to evaluate the effect of antioxidants on cancer and heart disease incidence over an eight year period.

The highest total and insoluble dietary fiber intakes were associated with reductions in the risks of overweight and elevated waist-to-hip ratio, blood pressure, plasma apolipoprotein (apo) B, apolipoprotein B to apolipoprotein A-I ratio, cholesterol, triacylglycerols, and homocysteine. Fiber from cereals was associated with a lower body mass index, blood pressure, and homocysteine concentration; fiber from vegetables with a lower blood pressure and homocysteine concentration; and fiber from fruit with a lower waist-to-hip ratio and blood pressure. Fiber from dried fruit or nuts and seeds was associated with a lower body mass index, waist-to-hip ratio, and fasting apo B and glucose concentrations.

The findings of this study illustrate the significance of increasing fiber intake from various dietary sources. The results also indicate that 25 grams total dietary fiber per day is the minimum intake required to attain a significant protective effect against cardiovascular disease, and that total dietary fiber intakes of 30-35 grams/day will likely provide an even greater protective effect.

American Journal of Clinical Nutrition, Vol. 82, No. 6, 1185-1194, December 2005

Resveratrol may help protect against Alzheimer's

A study published in the November 11 issue of the Journal of Biological Chemistry has shown that resveratrol, a compound found in grapes, red wine, peanuts and berries, lowers the levels of the amyloid-beta peptides, which cause much of the neurological damage associated with Alzheimer's disease. Researchers administered resveratrol to cells which produce human amyloid-beta and tested the compound's effectiveness by analyzing amyloid-beta levels inside and outside the cells. They found that amyloid-beta levels in the treated cells were much lower than those in untreated cells. It is thought that resveratrol acts by stimulating the degradation of these amyloid-beta peptides.

Although more research is needed, researchers suggest that this natural compound may have a therapeutic potential in Alzheimer's disease. Resveratrol is currently being researched for a potential role in fighting other human amyloid-related diseases such as Huntington's, Parkinson's and prion diseases.

J. Biol. Chem. Vol. 280; Issue 45: 37377-37382, November 11 2005.