Safety and effectiveness of weight reduction using a very-low-calorie formulated food

Careful medical and laboratory monitoring of 27 subjects during a 28-day use of a 330-calorie (Cal)/day liquid formula, with weight loss averaging 9.1 kg (range, 3.2 to 19.1 kg), included a 22-factor automated blood chemistry analysis, BP, hematology, urine analysis, lipid profile, delayed cutaneous hypersensitivity, differential cell count, ECG, and Holter monitoring. Results suggest that very-low-calorie diets can be an effective and safe means of substantial weight reduction. Cautions for specific individuals are noted. The possible beneficial effects on hypertension and on serum cholesterol and triglycerides levels are discussed.

[Clinical study of a prepared reducing diet: adequacy of the vitamin-mineral contribution in comparison to the nutritional and immunity status]

The Authors studied the effectiveness and safety of a commercial hypocaloric diet on 11 obese postmenopausal women. During the experimental period 1 meal/day has been replaced with a chemically defined low calories product. Different parameters have been evaluated to assess the nutritional status 1), anthropometric: weight, skinfold thickness, arm muscle circumference; 2) biochemical total plasma proteins, transferrin, vitamins A, E, C, B12, folic acid; plasma iron, hemoglobin, MCV, RBC; 3) immune status (T lymphocytes and immunoglobulins). Moreover blood sugar, cholesterol and triglyceride levels, as well as blood pressure have been taken into account. All the possible side effects and the diet acceptance for all the patients have been scored. After 1 month all the abnormal conditions (weight, cholesterol, blood pressure) improved, while the nutritional status and immune response remained at an optimal level.

Time-calorie displacement diet for weight control: a prospective evaluation of its adequacy for maintaining normal nutritional status

An unsupplemented 1000 kcal (4186 kJ) diet emphasizing large quantities of unrefined complex carbohydrates was evaluated for nutritional adequacy in a 20-week weight-control program for obese adults. Assessment of nutritional status, routinely obtained upon admission, was repeated at approximately 10-week intervals on 26 patients who were losing weight while adhering to the dietary guidelines. At least one repeat assessment was obtained on all 26 patients: 13 had follow-up assessment at 10 weeks, three at 20 weeks, and ten at both 10 and 20 weeks. Weight loss averaged 0.7 kg/wk over an average of 15 weeks with a mean energy intake of 1020 kcal (4270 kJ), 55 percent of baseline. At each follow-up assessment mean skinfold thickness fell significantly whereas muscle mass was maintained according to arm muscle circumference and creatinine-height index. Mean blood levels of retinol, beta-carotene, folate, vitamin B12, ascorbic acid, thiamin, riboflavin, pyridoxine, iron, transferrin saturation and calcium excretion remained within normal limits throughout treatment. Ascorbic acid levels rose significantly. The results indicate that the experimental diet, without supplementation, can fulfil nutritional requirements while restricting energy intake for weight reduction.

Estimates of food quantity and calories: errors in self-report among obese patients

We report three studies that examine the accuracy and usefulness of food records among dieting obese patients. In study 1 errors in quantity and calorie estimates for 10 common foods averaged 63.9% (quantity) and 53.4% (calories). The results of study 2 indicate that only 53% of entries in daily food records were specified enough to permit objective estimates of the calories consumed. In study 3, blind raters could not predict weight loss based on subjects' self-recorded behavior changes. Collectively, these results question the utility of food records for estimating energy intake or predicting weight loss.

Nitrogen economy during very low calorie reducing diets: quality and quantity of dietary protein

Controversy exists whether protein quantity or quality affect "nitrogen sparing" or physical health while subsisting on very low calorie diets. Therefore, in 38 obese men, nitrogen economy was evaluated over 2 months periods using one of five regimens: 1) 400 kcal high quality protein: 2) 400 kcal low quality protein; 3) 500 kcal 55 g protein natural food; 4) total fasting with potassium; and 5) total fasting without potassium. Up to the 20- and 40-day intervals, mean cumulative nitrogen deficity for all three diet groups was the same but 60% lower than with total fasting. However, within groups, individual capability to conserve nitrogen varied over as much as 2.8-fold. All 10 subjects of diet groups 1 and 2 had negative nitrogen balances to day 21, and six of these subjects were still negative by day 40. The improvement in nitrogen conservation and the ability to attain nitrogen equilibrium was unrelated to the differences in protein quantity and quality. Intake of essential or branched-chain amino acids was also unrelated to the efficiency of nitrogen conservation, as were insulin, glucagon, and 3-hydroxybutyrate levels. The only indicator correlating positively with nitrogen deficit was a fall in complement C3 (r = 0.87). Despite the extent of overall nitrogen loss, no cardiac arrhythmias were observed with either the high or low quality protein diet.

Elemental content of predigested liquid protein products

Eight commercially available partially digested gelatin liquid products that have been used as a source of protein in dietary regimens for weight reduction and for protein supplementation were analyzed for their elemental composition. These products were prepared either by dry ashing or wet digestion techniques that were suitable for the analysis of individual elements by their respective analytical methods. Analytical methods used to assess the elemental content included inductively coupled argon plasma emission spectrometry for Ca, Mg, P, Fe, Zn, Cu, Mn, Ni, Mo, V, Be, Co, Cr, Tl, Al, Te, Sn and Sb; atomic absorption spectrophotometry for Na and K; hybride generation with atomic absorption spectrophotometry for Se and As; anodic stripping voltammetry for Cd and Pb; and ion selective electrode for F. The content of almost all of the elements in these products was extremely low compared with the amounts supplied daily for normal individuals by usual sources of dietary protein, the adult United States Recommended Daily Allowances, and typical intakes from the Total Diet Study. The following elements were not detectable in significant amounts in these products by inductively coupled argon plasma emission spectrometry: Mo, V, Be, Co, Cr, Tl, Al, Te, Sn, and Sb. The results suggest that use of these predigested liquid protein products as a sole source of nutriment will result in an inadequate intake of all of the essential elements. These products contained insignificant amounts of Ce and Pb, nonessential toxic elements.

Effects of high-protein, low-carbohydrate dieting on plasma lipoproteins and body weight

Twenty-four obese but otherwise normal men and women were followed for: Two weeks on their usual food intake; eight weeks on a high-protein, low-carbohydrate diet; and then again for two weeks on their usual diet. During this time, several metabolic parameters were measured bimonthly. The high-protein, low-carbohydrate dieting resulted in substantial weight loss, probably due to a combination of salt and water loss, as well as caloric restriction. Plasma triglycerides fell as well. Significant increases occurred in LDL-cholesterol, uric acid, and free fatty acid levels. HDL-cholesterol levels failed to rise despite significant weight loss, indicating that the previously reported relationship between HDL-cholesterol and weight may be dependent, in part, on the composition of the diet.

Relationship of dietary regimens to success, efficiency, and cost of weight loss

One hundred twenty-five subjects in a behaviorally oriented, weight loss program that used several dietary patterns were retrospectively grouped according to the percentage of time they followed one of four dietary regimens: (a) Group 1--partial fasting, 400 kcal; (b) group 2--600 kcal; (c) group 3--1,200 to 1,500 kcal; and (d) group 4--failure to diet. The groups were described and compared regarding program completion, i.e., success and cost of weight loss. Groups 1 and 2 did significantly better than the other two in nearly all respects. Group 1 did better than Group 2 on program completion; the reverse was true when success of those completing 75 and 100 per cent of the program was compared. Groups 1 and 2 did not differ significantly on success variables.

[Metabolic studies during the comparison of a reducing diet with standard nutriton in volunteers]

Using human volunteers the metabolic alterations during standardized nutrition (2,000 kcal/day = 8,400 kJ/day) and during energy-reduced nutrition (1,180 kcal/day = 6,000 kJ/day) with a carbohydrate-containing semiformula diet were investigated. Evaluating the concentrations of blood glucose, serum insulin and serum-free fatty acids it was demonstrated that the nutrition-induced metabolic alterations between the meals (i.e. hyperinsulinemia, low fatty acid concentrations) were not normalized in the group using the standardized diet. In contrast in the group with energy-reduced diet (240 kcal/meal = 1,000 kJ) the concentrations of serum-free fatty acids and of serum insulin reached the fasting values before the next meal. The concentrations of triglycerides and of urea show merely slight reactions following the meals. A rise in concentration of these two parameters is found after the last meal. It is concluded that with the standardized diet the absorption phase following the meals lasts for at least 4 h, whereas the absorption is ended within 2-3 h following the energy-reduced meal. The results of these investigations are interpreted as follows. During a carbohydrate-containing semiformula diet the metabolic mechanisms including the regulations remain unaltered. An effect of the energy reduction is found merely before the next meal. It is assumed that the semiformula diet used does not induce ketosis or glucose tolerance due to a sufficient supply of carbohydrates. With regards to the metabolic effects measured this kind of semiformula diet is judged to be well balanced.

Consequences of modified fasting in obese pediatric and adolescent patients. I. Protein-sparing modified fast

Sixteen obese patients 9 to 16 years of age were treated with a protein-sparing modified fast for four weeks in a metabolic unit, using lean meat as the sole calorie-containing nutrient. Total weight loss was 7.11 +/- 0.33 kg (mean +/- SEM). One-half of the patients achieved positive daily nitrogen balance by the fourth week. Cumulative N balance was -28.8 +/- 10.0 gm. Serum albumin concentration remained normal. Hemoglobin and hematocrit values were stable, but decreases in total lymphocyte (P less than 0.005) and neutrophil counts (P less than 0.01) were noted. Cell-mediated immunity (four patients) remained normal. Protein synthetic and catabolic rates (two patients) revealed only minimal changes. Cumulative N balance correlated (P less than 0.01) with mean fasting serum insulin concentration, which was related (P less than 0.005) to body fat mass. The PSMF has therapeutic potential for achieving safe, rapid weight loss in severely obese older children and adolescents.

Very-low-calorie diet in the treatment of massive obesity: preliminary experience

Twenty-two consecutive obese patients were given very-low-calorie diet (VLCD) in the form of a casein and lactose preparation dissolved in orange juice containing 43.0 g protein, 30.4 g carbohydrate and 1.1 g lipid in a total of 317 kcal (1.3 MJ) daily. VLCD was given intermittently in eight-week periods alternating with three-week periods of conventional diet (900-1200 kcal, 3.8-5.0 MJ) to ensure recuperation of lean body mass and to establish a therapy which may facilitate indefinite patient compliance. In case of persisting hunger, diethyl-propion was given in small doses. The median observation time was nine weeks (range 1-37 weeks). The median weight loss was 15.5 kg (range 3.8-39.2 kg), and the median overweight decreased from 85.5 per cent (range 43-135 per cent) to 61.0 per cent (range 19-100 per cent). Blood glucose and cholesterol fell significantly (P < 0.01), and no major side-effects were observed.

Reducing diets in rats

Adult obese rats were restricted to equal intakes provided by four diets which varied widely in protein, fat and carbohydrate content. Loss in body weight and body fat was similar in all groups. The only significant dietary effect observed was a modest increase in the body protein content of the animals fed the high protein diets. Low carbohydrate--high fat--high protein diets, as expected, showed no advantage as reducing diets when compared to other diets on an equal calorie basis.