Metformin Decreases Food Consumption and Induces Weight Loss in Subjects with Obesity with Type II Non-Insulin-Dependent Diabetes

Metformin often promotes weight loss in patients with obesity with non-insulin-dependent diabetes mellitus (NIDDM). The mechanism may be attributed to decreased food intake. This study has tested the effect of metformin on satiety and its efficacy in inducing weight loss. Twelve diet-treated NIDDM women with obesity were randomly given two dose levels (850 mg or 1700 mg) of metformin or placebo at 0800 for three consecutive days followed by a meal test on the third day on three occasions using a 3times3 Latin square design. The number of sandwich canapes eaten in three consecutive 10-minute periods beginning at 1400 hours was used to quantitate food intake, and the level of subjective hunger was rated just before the sandwich meal with a linear analogue hunger rating scale at 1400 after a 6-hour fast. The prior administration of metformin produced a reduction in calorie intake after each of the two doses of metformin treatment. The 1700-mg metformin dose had the most marked appetite suppressant action. Similarly, hunger ratings were significantly lowered after metformin, and the effect was most pronounced after the administration of 1700 mg of metformin. To assess the efficacy of metformin in reducing bodyweight, 48 diet-treated NIDDM women with obesity who had failed to lose weight by diet therapy were first placed on a 1200-kcal ADA (American Diabetes Association) diet before being randomized to receive either metformin (850 mg) or placebo twice daily in a double-blind fashion for 24 weeks. A 4-week single-blind placebo lead-in period preceded and a 6-week single-blind placebo period followed the 24-week double-blind treatment period. Subjects treated with metformin continued to lose weight throughout 24 weeks of treatment; their mean maximum weight loss was 8 kg greater than that of the placebo group, with corresponding lower HbA1C and fasting blood glucose levels at the end of the active treatment period. These results indicate that metformin decreases calorie intake in a dose-dependent manner and leads to a reduction in bodyweight in NIDDM patients with obesity.     

What Do We Most Need to Learn about Food Intake Regulation?

Many mechanisms are known to contribute to the regulation of food intake. This notwithstanding, variations in food intake from day to day and deviations from daily energy balance are substantial and very readily tolerated. Yet, despite this very loose short-term adjustment of food intake to energy expenditure, most adults maintain stable body compositions during long periods of their lives. This is particularly puzzling when it occurs in the face of an ubiquitous supply of appealing foods and under circumstances that, in many ways, promote food consumption. Thus, the question arises as to why people in affluent societies eat substantially less on most days, than the amounts that they can so readily consume on high-intake days? In addition to conscious decisions, physiological phenomena restraining food consumption must be presumed to play an important role in limiting weight. But what are the phenomena that cause spontaneous reduction in food intake after a few days of overeating? Our ignorance about the nature and impact of these effects stands in the way of a better understanding of body weight regulation and of the factors responsible for the induction and maintenance of obesity.     

Dieting Status and Its Relationship to Weight,Dietary Intake,and Physical Activity Changes Over Two Years in a Working Population

The present study prospectively examined changes in dietary intake, physical activity and weight associated with self-reported efforts to lose weight in a cohort of 3671 men and women sampled from the general population. Dieting efforts, dietary intake, physical activity and weight were measured at two points in time, 24 months apart. At baseline, current dieters reported consuming fewer dairy products, sweets, meat, soft drinks and fried potatoes (all p's < .0001), and engaging more frequently in high-intensity physical activity (p < .0001) than those not currently dieting. At follow-up, current dieters reported consuming fewer sweets (p < .0001) and fried potatoes (p < .0008), and engaging more frequently in moderate-intensity physical activity (p < .02) than those not currently dieting. Prospectively, those who initiated weight-loss diets showed the largest decrease in consumption of sweets (p < .0001), soft drinks (p < .0001), and fried potatoes (p < .01), and increase in frequency of high-intensity physical activity (p < .0001) and moderate-intensity physical activity (p < .007). Those initiating weight-loss diets were the only group to lose weight (1 lb.). Those dieting at baseline but not at follow-up gained the most weight (4 lbs.). Self-reports of current dieting correspond to reported changes in dietary intake and physical activity, and to measured changes in weight over the same time period. Individuals who report dieting to lose weight have healthier eating and exercise patterns than those who do not report dieting.     

Bio-activity of marine cyanobacteria in the animal-based systems: Modulation of food intake, body weight and some haematological characters

With a view to assess the bioactive potential of the unexploited marine cyanobacteria available in abundance in the marine habitat, water-soluble fraction of the ethanolic extract of 12 different strains of marine cyanobacteria were administered to male rats and their impact on food intake, body weight and certain haematological characters including RBC counts, WBC-TC and DC, platelet counts, haemoglobin content and mean corpuscular haemoglobin was studied. The results suggest prospective applications as feed/nutritional supplements; among them, Spirulina subsalsa BDU 30311, Oscillatoria salina BDU 10142 and Phormidium valderianum BDU 20571 appear highly promising in this regard. Lyngbya sp. BDU 30601 and Pseudanabaena schmidlei BDU 30313 appear to contain one or more toxins and deter food intake and cause decrease in body weight. With Synechococcus elongatus BDU 30312 food intake increased over the control which was not commensurate with the change in body weight. The results relating to the haematological characters indicate bioactivity of the cyanobacteria in the animal-based systems, some of which are positive, whereas a few strains like Lyngbya BDU 30601 are negative, implying their pharmaceutical application.     

Diurnally cycling temperature and ventilation affect young turkeys' performance and sensible heat loss

The goals were to elucidate the effects of ventilation rate (VR) coupled with exposure to constant 20 °C or to diurnal temperature cycling on young turkeys' performance and sensible heat loss (SHL). In three experiments male British United Turkeys (BUT), from 3 to 6 weeks of age, were exposed to constant 20 °C, or to 35/25 °C or 30/20 °C diurnal temperature cycling, all at 50% RH and with VR (expressed as air velocity (AV)) ranging from 0.8 to 3.0 m s⁻¹. The 2nd and 3rd of these experiments included a positive control at constant 30 °C and VR of 1.5 m s⁻¹. Weight gain, feed intake, and feed efficiency were measured or calculated, as appropriate; SHL was calculated from measured surface temperature, and plasma concentrations of triiodothyronine (T₃) was determined in the 1st experiment. Changes of VR at constant 20 °C did not affect performance, but total SHL increased significantly with increasing VR. Under the 35/25 °C regime a significantly higher BW was recorded, with a similar pattern of feed efficiency, when VR during the hot part of the cycle was 1.5 or 2.0 m s⁻¹ than when it was 0.8 m s⁻¹. In the 3rd experiment, BW in the 35/20 °C treatment was significantly lower than that of the controls. In all experiments, turkeys maintained body temperature (T_b) within the normothermic range, and SHL varied with VR. It can be concluded that although diurnal temperature cycling reflects the natural situation, exposing young turkeys to constant 30 °C combined with optimal ventilation might yield the best performance results.