Reinhold G. Laessle

A comparison of the validity of three scales for the assessment of dietary restraint.

The construct validity of Herman and Polivys Restraint Scale (RS), the restraint factor of the Three Factor Eating Questionnaire (TFEQ-R), and the restraint scale of the Dutch Eating Behavior Questionnaire (DEBQ-R) were investigated by relating these scales to self-reported mean caloric intake per day and to other measures associated with disordered eating and figure consciousness. A factor analysis showed that the three restraint scales measure different components of the restraint construct. A high score on the RS was closely related to consequences of mostly unsuccessful dieting, such as disinhibited eating and weight fluctuations, but not to successful overall caloric restriction in everyday life. High scores on the TFEQ-R and the DEBQ-R represented the more successful dieting behavior component of restraint. The three scales have in common a motivational component of restrained eating, including concerns about shape and weight, and desire for thinness.

Behavioral and biological correlates of dietary restraint in normal life

Based on laboratory results, restrained eating has been linked to the development of binge eating and eating disorder syndromes such as bulimia nervosa. This study was designed to extend the scope of investigation of the concept of restrained eating beyond the laboratory. Eating behavior and biochemical indices of nutritional state were investigated in 60 young women, who were divided in restrained and unrestrained eaters by questionnaire. Seven-day records of food intake showed that the high-restraint group ate around 400 kcal a day fewer than the low-restraint group. Group differences in actual macronutrient intake and long-term food preferences pointed to a qualitatively altered eating pattern in restrained eaters. Actual protein portion was higher in restrained eaters. They tried to avoid calorie dense food items of high carbohydrate and fat content. Instead, they preferred food regarded as low-caloric and healthy. Plasma levels of triiodothyronine and glucose, which could be taken as indices of long-term adaptation to starvation, were not decreased in the high-restraint group. However, significantly higher levels of triglycerides in restrained eaters may reflect a biological state due to short-term starvation. The results indicate that the concept of dietary restraint predicts eating behavior not only under experimental conditions, but also in normal life. As a consequence of altered eating patterns, psychological and physiological deprivation can be hypothesized in restrained eaters, making them prone to the occurrence of overeating.

Dieting influences the menstrual cycle: vegetarian versus nonvegetarian diet

Eighteen healthy, normal-weight women aged 19 to 27 years who had regular ovulatory menstrual cycles volunteered for the study. Blood was drawn on Mondays, Wednesdays, and Fridays throughout the control cycle and during a 6-week diet period that began with commencement of a new cycle. Nine women followed a vegetarian diet and nine a nonvegetarian diet. Both groups lost an average of 1 kg body weight/week. Seven of nine women in the vegetarian group became anovulatory. During the vegetarian diet the average luteinizing hormone (LH) values were significantly decreased during the midcycle and the luteal phase. Estradiol (E2) and progesterone (P) values were significantly lower during the luteal phase. In contrast, the nonvegetarian group did not show significant reduction of LH, E2, and P values during any part of the menstrual cycle. Seven of nine women in the nonvegetarian diet group maintained ovulatory cycles with no changes in cycle length or in the length of the follicular phase. In one woman who became anovulatory, E2 values did not increase during the follicular phase.

Mood changes and physical complaints during the normal menstrual cycle in healthy young women.

Significant emotional and physical symptoms have been linked to hormonal changes during the menstrual cycle. A critical evaluation of the available studies questions the commonly held belief in menstrual-cycle-related complaints in the majority of normal women. The present study investigated changes in mood, somatic complaints and vegetative variables during the menstrual cycle in 30 healthy young women. Normal cycle function was evaluated and cycle phases were defined according to endocrine data. For all subjects, blood samples were taken at least three times a week to measure estradiol and progesterone. Daily ratings of psychological variables revealed no significant changes in global mood or depression over the cycle. Somatic complaints such as abdominal pain and breast tenderness were significantly related to the luteal, premenstrual, and menstrual phases. Appetite increased in the periovulatory and premenstrual phases. There was a tendency for sexual interest to be highest in the post-menstrual period. Affect and vegetative variables showed no association with hormone levels but were significantly correlated with subjective stress ratings. We conclude that in most healthy young women, cycle-related hormone fluctuations are not accompanied by marked affective changes. Specific physical complaints, however, do occur, particularly in the luteal, premenstrual, and menstrual phases.

Differences in food-choice frequencies between restrained and unrestrained eaters

Reported frequency of consumption for certain food items was studied in young normal-weight women, classified into 19 unrestrained and 20 restrained eaters by the Three-Factor Eating Questionnaire of Stunkard & Messick (1985). Neither group differed in the consumption of basic foods and snacks but restrained eaters showed a strong tendency to avoid fat. A large percentage of this group was used to consuming artificial sweeteners and other calorie-reduced foodstuffs. These qualitative alterations in the everyday eating behavior of restrained eaters may be one of the links between dietary restraint and binge eating.

Biological and psychological correlates of intermittent dieting behavior in young women. A model for bulimia nervosa

The eating disorder bulimia nervosa is characterized by alternating periods of strict dieting and overeating. Patients also report mood fluctuations, frequent eating related thoughts, fear of loss of control over eating, impairment of cognitive abilities such as concentration, and somatic complaints. The present study attempted to clarify to what extent these symptoms are consequences of the dieting behavior. Nine healthy young women, classified as unrestrained eaters, were set on a intermittent dieting schedule over 4 weeks. Four days each week (Tue, Wed, Thu, Fri) they had to reduce their intake below 600 kcal/day, the other 3 days they could eat without restrictions. Psychological variables were assessed by means of a standardized diary. Biological indices of starvation were also measured repeatedly. There was no substantial weight loss after the 4 weeks, although subjects had significantly increased levels of beta-hydroxybutyric acid during the dieting periods, and decreased levels of t3 after 2 weeks. The reported tendency to overeat and the actual calorie intake during the days of unlimited access to food showed a significant increase over the 4-week period. Eating-related thoughts, feelings of hunger, and fear of loss of control were significantly more frequent during periods of dieting, compared to days of normal eating. Subjects also reported worse mood, heightened irritability, difficulties concentrating, and increased fatigue. These results suggest that a substantial part of symptoms of bulimic patients might be associated with the frequent periods of an extremely restrained eating behavior.

Diet-induced menstrual irregularities: effects of age and weight loss

Luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), and progesterone (P) levels were followed in 22 healthy, normal-weight women (aged 19 to 30 years) for a control and a diet menstrual cycle. During the diet cycle, they lost weight on a high-carbohydrate, vegetarian, 1000-calorie diet. During the control cycle, luteal phase in 5 subjects failed to meet the criteria: length greater than or equal to 8 days and P maximum greater than or equal to 6 ng/ml; during the diet cycle, the number of subjects who failed to meet these criteria was 14 (chi-square test, P less than 0.02). No evidence of follicular phase disturbance was observed during the diet. Age and weight loss significantly changed parameters of the diet luteal phase: length and area under LH, FSH, E2, and P curves. Generally, hormone plasma concentrations during the luteal phase were lower the younger the age and the greater the weight loss.

Dieting causes menstrual irregularities in normal weight young women through impairment of episodic luteinizing hormone secretion

Thirteen healthy, normal weight young women were studied throughout a control cycle and a diet cycle, during which they lost 1kg per week on a vegetarian 800kcal diet. Blood was sampled daily in the morning, and at weekly intervals, collected at 10-minute intervals for 6 hours. Follicle growth was monitored by ultrasonic measurement. All subjects showed normal cyclic gonadal function during the control cycle. Cyclic gonadal function remained unaltered in two subjects during the diet cycle. No dominant follicle developed in seven others, while another four showed apparently normal follicular development but impaired progesterone secretion by the corpus luteum. Comparison of both cycles revealed that episodic luteinizing hormone (LH) secretion during the follicular phase was altered by dieting. Average LH concentrations and the frequency of episodic secretions were significantly reduced during the follicular phase but not during the luteal phase. Follicle-stimulating hormone was unaltered.

Overweight and basal metabolic rate in boys with attention-deficit/hyperactivity disorder

We investigated a possible association between attention-deficit/hyperactivity disorder (ADHD) and overweight by measuring weight status and energy expenditure (basal metabolic rate, BMR) in 39 ADHD-boys with hyperactivity (mixed hyperactive/impulsive and inattentive or predominantly hyperactive/impulsive) and 30 healthy boys. The age range for the total group was 8–14 years. Weight and height were measured by a calibrated scales and stadiometer. Body mass index standard deviation scores (BMI-SDS) were calculated. BMR was determined by indirect calorimetry. Significant differences were obtained between the ADHD- and the control-group, but not between ADHD-subgroups. Both BMI-SDS and BMR were higher in the group of ADHD-boys, whereby the differences were more marked when they were older. More overweight and obese subjects were found in the ADHD-sample. Impulsive behavior in ADHD-boys with hyperactivity may lead to an increased food intake, which is then likely to overcompensate the heightened energy expenditure.

Cerebral Atrophy and Vigilance Performance in Patients with Anorexia nervosa and Bulimia nervosa

The relationship between ventricular size, as a measure of brain atrophy, and performance on a vigilance task was investigated in 39 patients with anorexia or bulimia nervosa during the acute stage of their illness. Compared to normal controls, the patients performed significantly more poorly in the cognitive task. Half of the patients displayed enlarged ventricles. However, the patients with ventricular dilatation did not perform worse in the cognitive test than patients with normally sized ventricles. Other clinical characteristics, such as symptom severity or duration of illness, were also not correlated with ventricular size. These results support the interpretation that cerebral atrophy per se does not have severe consequences on the neuropsychological or psychopathological status in eating disorder patients.