Weight management using a meal replacement strategy: meta and pooling analysis from six studies.

OBJECTIVE: Although used by millions of overweight and obese consumers, there has not been a systematic assessment on the safety and effectiveness of a meal replacement strategy for weight management. The aim of this study was to review, by use of a meta- and pooling analysis, the existing literature on the safety and effectiveness of a partial meal replacement (PMR) plan using one or two vitamin/mineral fortified meal replacements as well as regular foods for long-term weight management. DESIGN: A PMR plan was defined as a program that prescribes a low calorie (>800or=25 kg/m(2), were evaluated. Studies with self-reported weight and height were excluded. Searches in Medline, Embase, and the Cochrane Clinical Trials Register from 1960 to January 2001 and from reference lists identified 30 potential studies for analysis. Of these, six met all of the inclusion criteria and used liquid meal replacement products with the associated plan. Overweight and obese subjects were randomized to the PMR plan or a conventional reduced calorie diet (RCD) plan. The prescribed calorie intake was the same for both groups. Authors of the six publications were contacted and asked to supply primary data for analysis. Primary data from the six studies were used for both meta- and pooling analyses. RESULTS: Subjects prescribed either the PMR or RCD treatment plans lost significant amounts of weight at both the 3-month and 1-year evaluation time points. All methods of analysis indicated a significantly greater weight loss in subjects receiving the PMR plan compared to the RCD group. Depending on the analysis and follow-up duration, the PMR group lost approximately 7-8% body weight and the RCD group lost approximately 3-7% body weight. A random effects meta-analysis estimate indicated a 2.54 kg (P<0.01) and 2.43 kg (P=0.14) greater weight loss in the PMR group for the 3-month and 1-y periods, respectively. A pooling analysis of completers showed a greater weight loss in the PMR group of 2.54 kg (P<0.01) and 2.63 kg (P<0.01) during the same time period. Risk factors of disease associated with excess weight improved with weight loss in both groups at the two time points. The degree of improvement was also dependent on baseline risk factor levels. The dropout rate for PMR and RCD groups was equivalent at 3 months and significantly less in the PMR group at 1 y. No reported adverse events were attributable to either weight loss regimen. CONCLUSION: This first systematic evaluation of randomized controlled trials utilizing PMR plans for weight management suggests that these types of interventions can safely and effectively produce significant sustainable weight loss and improve weight-related risk factors of disease.

Lipoprotein responses to weight loss and weight maintenance in high-risk obese subjects.

OBJECTIVE: To examine changes in plasma lipids and lipoproteins after 51 months of reduced energy intake and sustained weight loss. METHODS: One-hundred patients were randomized to one of two dietary interventions for 3 months (weight loss period). Groups A and B received an energy-restricted diet plan of 5.2-6.3 MJ/day but group B was further instructed to replace two of three meals with a nutrient-fortified liquid meal replacement (MR). Upon completion of the weight loss period, all patients were given the same instructions regarding energy intake and were advised to use one MR daily. Body weight and 7 day food diaries were measured monthly or bimonthly and blood lipids at baseline, 3, 9 and 51 months. RESULTS: Of the original 100 patients 75 had completed 4 y. Of those 75, 73 had complete lipid records. Baseline body weights of Groups A and B were 90.7+/-14.0 and 91.6+/-9.8 kg, respectively. The percentage change in total cholesterol (%DeltaTC) decreased in a linear fashion with increasing weight loss, when all data was combined, but did not approach statistical significance (P< or =0.26, r=0.02). Further regression analysis found a significant negative linear relationship (P< or =0.0001, r=0.69) between initial total cholesterol (TC) concentrations and %DeltaTC. Hence, data from 27 of the 73 completers who exhibited an elevated serum total cholesterol (> or =6.2 mmol/l) were isolated and analyzed further. Baseline TC was 6.75+/-0.64, 5.85+/-0.63 at 9 months (P<0.05) and 5.76+/-0.52 mmol/l at 51 months (P<0.05). Similar values for VLDL-cholesterol were 1.33+/-0.80, 0.74+/-0.24 and 0.66+/-0.21 mmol/l by 51 months (P<0.05). Weight decreased by 5.2+/-5.1, 7.6+/-4.9 and 6.7+/-4.6% at 3, 9 and 51 months, respectively. CONCLUSION: Continuous energy restriction associated with a clinically meaningful weight loss significantly improved the lipid profile of high-risk patients. Similar weight and diet changes occurring in patients with normal plasma cholesterol were either increased or without affect.

Foods, health claims, and the law: comparisons of the United States and Europe.

Government, academia, and the food industry can play a significant role in the identification of healthy foods and ingredients important for weight management and health. The U.S. Food and Drug Administration developed regulations that define specific food categories for weight management and health. These categories include foods for special dietary uses and medical foods. Medical foods are classified for use in specific disease states and require a physician's recommendation and continuous monitoring. The European regulations specify energy-restricted foods as a subcategory of food for particular nutritional uses, which includes infant formula, medical foods, and foods for sports. European standards for energy-restricted diets have been established, leaving little flexibility for change. Three categories exist (i.e., very-low-calorie diets [450 to 800 kcal], low-calorie diets [800 to 1200 kcal], and meal replacements [200 to 400 kcal]). No claims on anticipated weight loss can be made even where significant clinical research has demonstrated long-term efficacy, thereby preventing informed choice management. Dramatic changes in lifestyle (e.g., disruption of the family unit, altered eating occasions, fast foods, and food grazing) have resulted in an epidemic of obesity and chronic disease. Regulating food selection or dietary patterns to limit the epidemic is not realistic. However, stimulating government health agencies and the food industry to increase public awareness through educational programs and regulating the definition of acceptable methods and products can provide an environment for change. A consensus is needed among academia, government, and industry for appropriate food labeling and claims. These actions are needed to help individuals make healthy food selections and maintain a healthy weight. Public health initiatives should change consumer attitudes with programs that are simple, affordable, effective, and accessible.

Morphologic alterations associated with decreased cerebrospinal fluid pressure in chronic bovine hypervitaminosis A.

Arachnoid granulations and villi, choroid plexuses, and ependymal epithelium from 18 male Holstein-Friesian calves fed 108 (control), 8,800 (midly toxic), or 17,600 (severely toxic) mug of vitamin A/kg of live weight per day for 12 weeks were examined by light and electron microscopy for structural changes which could be used to explain the decreased cerebrospinal fluid (CSF) pressure seen in chronic hypervitaminotic A animals. In the toxic calf group, granulations were reduced to approximately two-thirds the size of those in the control calves, with the fibrous cap particularly being thinner and smaller. Second, height of epithelial cells of the lateral and 3rd ventricular choroid plexuses decreased significantly and that of the 4th ventricular choroid plexus, only slightly, as vitamin A intake increased. Structural differences of ependymal cells were not apparent between control and hypervitaminotic A calves. It is hypothesized that the thinner and less extensive fibrous cap of the arachnoid granulations in the toxic calves may result in increased permeability to CSF outflow.