[Significance of intentional weight loss on health]

The aim of the present study was critically to review how intentional weight loss in overweight and obesity influences mortality. No randomized weight loss intervention trial has included mortality as an end-point. However, even minor weight loss causes beneficial changes in risk factors for cardiovascular disease, whereas the vast majority of observational studies have linked weight loss to excess mortality. Most observational studies do not have information on intentionality of weight loss and suffer from other methodological limitations making inferences from these studies difficult. Given the available observational evidence, the possibility that intended weight loss may cause some increased mortality cannot be excluded. However, considering the totality of the evidence on effects of intended weight loss among overweight and obese subjects, there may be other benefits, such as: psycho-social and physical well-being, risk factor improvement, decreased morbidity, and in certain high-risk subgroups decreased mortality. Treatment of obesity is therefore recommended, particularly in the presence of risk factors or complications.

[Spontaneous weight loss in young subjects of normal weight after 11 weeks of unrestricted intake of a low-fat/high-fiber diet]

The present study investigated the spontaneous, unintended body weight changes observed during the first 11 weeks of an eight months' ad libitum low-fat/high-fibre diet (25.5 energy-% fat, 58.5 energy-% carbohydrate, 3.9 g dietary fiber/MJ), primarily aimed at investigating changes in blood lipid concentrations. Subjects were normal-weight, young, healthy students, 24 in the intervention group, and 24 in the control group (no diet). After 11 weeks, an overall decrease in body weight (1.3 +/- 0.4 kg) (mean +/- SEM) (p < 0.01) and fat mass (1.6 +/- 0.2 kg, p < 0.001) was observed in the intervention group. Fat-free mass remained unchanged. Initial body weight and fat mass correlated significantly to changes in body weight and fat mass. No changes were observed in the control group. In conclusion, the ad libitum intake of a low-fat/high-fibre diet led to a spontaneous, small loss of body weight and fat mass in young, normal-weight subjects.

[Prognostic markers for weight loss in the treatment of obesity]

The aim of the study was to identify prognostic metabolic markers for long-term weight loss outcome in obese women. Forty female obese patients underwent a dietary intervention of 36 weeks treatment with a 4.2 MJ/d low-fat high carbohydrate diet and were followed-up two and a half years after cessation of treatment. The maximum weight loss (mean 16.2 kg. 95% CI 14.2-18.2) was positively associated to pre-treatment 24-h energy expenditure (EE) (p < 0.01), fat oxidation (%) (p < 0.02), plasma dihydrotestosterone (DHT) (p < 0.01), and to postprandial noradrenaline concentration (p < 0.04). Together these factors could explain 41% of the variation in maximum weight loss. After 36 weeks only 24-h EE and DHT had predictive power on weight loss. Weight losses in upper and lower tertiles of DHT concentrations were 17.7 kg (14.1-21.4) and 9.8 kg (6.2-13.3) (p < 0.02) and the adjusted relative risk of losing < 10 kg in the upper compared to the lower DHT tertile was 12% (4-32%). At two and a half years follow-up 21 patients had maintained some of the weight loss (54%), while 14 patients had maintained > 5 kg weight loss (36%). High levels of pre-treatment DHT were also associated with better weight loss at two and a half years follow-up. The study suggests that long-term weight loss outcome may be predicted by pre-treatment metabolic and hormonal factors in obese women.

[Nutritional assessment of recipes distributed to households]

This study examines the nutritional standards of recipes in six pamphlets distributed to all households in Denmark. The publications all purport to contain recipes for a healthy diet. The nutritional values given in the publications are compared to calculated values and found to be almost identical. The fat content of most of the recipes is too high: recipes in the first three pamphlets had a median fat energy content of 50%. The later publications are better: 40% in two pamphlet and 33% in the last pamphlet. It is likely that the high fat content of the household distributed pamphlets contributes to the continued high fat content in the Danish diet. We suggest that the fat energy percent should be less than 30 in half the recipes and be only 30-35 on average. The energy content should not be greater than 2.5-3.5 MJ per portion. Nutritional value estimates and the nutrition information should be standardized so as to make them more accessible for the consumer who wishes to make healthy diet choices, and more instructive generally concerning general principles of an appetizing and healthy diet.

[Objective assessment of the habitual dietary fat content in patients with obesity]

A diet rich in fat may be an important precipitating factor of obesity, but studies on this relation have been hampered by the lack of an objective method to assess habitual dietary fat content. We measured 24-h fat oxidation in a respiration chamber in 38 overwight or obese and 35 nonobese women, and used it as an estimate of habitual dietary fat energy (%). After adjustment for confounders, obese women had higher oxidative fat energy than nonobese women [40.2% (37.8-42.6) vs. 36.0% (33.6-38.5), p < 0.02]. Adjusted oxidative fat energy (%) increased with increasing size of fat mass, and this relation suggest that a 10-kg change in fat mass may be caused by a change in dietary fat energy of > or = 1.6%. This objective assessment supports the contention that obese subjects consume a diet with a higher fat content than nonobese individuals, and the high-fat diet may have causal importance for the development and maintenance of obesity.

[The effect on health of dietary antioxidants and antioxidant supplements]

Reactive free oxygen radicals are formed in the reactions involved in normal cell metabolism. This formation is closely regulated e.g. by dietary antioxidants. Present knowledge suggests that an imbalance, with surplus of free radicals, can play a role in the pathogenesis of certain types of cancer, atherosclerosis, and cataract. A number of epidemiological studies have demonstrated a reduced risk of developing these diseases in persons who consume a diet with a high content of vegetables and fruit, which contains large quantities of the antioxidants: beta-carotene, vitamins C and E. Intervention studies, using supplements of these antioxidants, have so far not been able to show a beneficial effect. The apparently protective effect of fruit and vegetables may be due to other active ingredients. In Denmark the average intake of vegetables and fruit is low, and it is estimated that an increased consumption of these foods could reduce the occurrence of certain cancer types and atherosclerosis. In contrast, there is no evidence that antioxidant supplements would provide protection against disease, and their safety remains to be established.

[The importance of nutrition for the prevention of osteoporosis]

The prevalence of osteoporosis is increasing, and is a significant burden on society. Dietary composition is an important determinant of the bone mineral density in the growth period, and of the magnitude of the age related bone mineral loss, in particular among postmenopausal women. Therefore, an improvement of the diet has an important role in the prevention of osteoporosis. A sufficient intake of calcium and vitamin D can reduce the risk of fractures in postmenopausal women, and it is likely that a low calcium intake may affect peak bone mass negatively. Calcium in the Danish diet comes mainly from dairy products. Half a litre of milk and 25 g of cheese will cover most people's calcium requirement. Part of the calcium requirement may also be covered by consuming other foods such as cabbage, broccoli and beans. Children, adolescents and elderly individuals who avoid dairy products are recommended to take a calcium supplement. The status of vitamin D among the elderly can be improved by a daily outdoor stay and by a frequent intake of fatty fish such as herrings. Elderly persons who stay indoors are recommended to take a vitamin D supplement.

[Effect of 3-month exercise training on daily energy expenditure in formerly obese women with reduced and stable weight]

Predisposition to obesity has been suggested to be related to a low energy expenditure (EE). This condition could be counteracted by physical exercise. In the present study we wanted to elucidate if aerob training could increase sedentary 24-hour energy expenditure in formerly obese subjects. Seven reduced-obese premenopausal women were studied in a respiration chamber before and after a three month period of aerobic training. No significant effects of training were seen on daytime, sleeping or total 24-hour EE. However, the change in daytime EE was positively correlated to the change in VO2max. Sleeping and 24-hour respiratory quotients were slightly increased after the training period. In order to reveal a possible role of the sympathetic nervous system in the observed effect of training, additional experiments were performed with beta blockade. However, no interactions between training and beta blockade were found.

Safety and efficacy of long-term treatment with ephedrine, caffeine and an ephedrine/caffeine mixture

In a randomized, placebo-controlled, double blind study, 180 obese patients were treated by diet (4.2 MJ/day) and either an ephedrine/caffeine combination (20mg/200mg), ephedrine (20mg), caffeine (200mg) or placebo 3 times a day for 24 weeks. 141 patients completed this part of the study. All medication was stopped between week 24-26 in order to catch any withdrawal symptoms. From week 26 to 50, 99 patients completed treatment with the ephedrine/caffeine compound in an open trial design, resulting in a statistically significant (p = 0.02) weight loss of 1.1kg. In another randomized, double-blind, placebo-controlled 8 week study on obese subjects we found the mentioned compound showed lean body mass conserving properties. We conclude that the ephedrine/caffeine combination is effective in improving and maintaining weight loss, further it has lean body mass saving properties. The side effects are minor and transient and no withdrawal symptoms have been found.

Reduced plasma noradrenaline concentrations in simple-obese and diabetic obese patients

1. Obesity may be associated with a decreased activity of the sympathetic nervous system and also with a deficiency of the response to stimuli activating the sympathetic nervous system. As insulin activates the sympathetic nervous system, the present study was undertaken to measure the plasma noradrenaline concentration in the fasting state and after 75 g of oral glucose in simple-obese patients (n = 13), in non-insulin-dependent (type 2) diabetic patients (n = 37) and in normal control subjects (n = 12). 2. The fasting plasma noradrenaline concentration was similarly reduced in the simple-obese group and in the diabetic obese group compared with the control group (P = 0.005). The glucose-induced increase in plasma noradrenaline concentration was normal in the simple-obese group, but was abolished in the obese diabetic patients (P = 0.008). 3. Step-wise regression analysis indicated that independent effects on the fasting plasma noradrenaline concentration were exerted by age (r = +0.32, P = 0.002), glucose concentration (r = -0.32, P = 0.02) and the degree of obesity (r = -0.37, P = 0.007), but not by plasma insulin concentration. 4. These results show that obese patients have a reduced fasting plasma noradrenaline concentration independently of accompanying diabetes, but that the response of noradrenaline to oral glucose is only abolished in the obese diabetic patients.

[Obesity and diabetes as side-effects of beta-blockers]

Overweight and obesity may develop in individuals with genetically determined low resting energy expenditure. Drugs are among the recognised precipitating factors. The obesity promoting impact of beta-blockers is, however, less well known. Resting energy expenditure, and thermogenesis induced by stimuli such as meals, cold and heat exposure, stress and anxiety, have a facultative component mediated by the sympathoadrenal system through catecholamines working on beta-adrenoceptors. Treatment with beta-blockers reduces the facultative thermogenesis by 50-100 kcal/d, which corresponds to the weight gain of 2-5 kg/year reported in clinical trials. Treatment with beta-blockers also results in insulin resistance, which may aggravate existing diabetes and elicit diabetes in predisposed patients. Overweight and obesity are frequently complicated with hypertension and angina pectoris, which are often treated with beta-blockers. Obesity is associated with a defective sympathetic activity, and treatment with beta-blockers may further reduce facultative thermogenesis and promote weight gain. The consequence may be aggravation of hypertension, insulin resistance and other atherogenic factors. The causal therapy of android overweight and obesity complicated with diabetes or hypertension is a sufficient weight loss. If pharmacological treatment is inevitable, combined treatment with diuretics and ACE-inhibitors are most appropriate.