Extended use of foods modified in fat and sugar content: nutritional implications in a free-living female population.

The nutritional implications of the consumption of reduced-fat and reduced-sugar foods were assessed in nonobese, free-living female consumers in a 10-wk intervention trial. Subjects in control (C; n = 13), reduced-fat (RF; n = 17), and reduced-sugar (RS; n = 19) groups, all initially nonusers of reduced-fat and reduced-sugar products, kept 4-d food-intake records to establish energy and macronutrient intakes at baseline and at 2,4,7, and 10 wk. Groups RF and RS were instructed to use reduced-fat and reduced-sugar foods, respectively, ad libitum in place of habitually consumed foods with traditional composition, whereas group C was to maintain their usual diet. All foods were purchased by subjects in normal retail outlets and consumed at home. Analyses revealed no main or interactive effect of group on reported energy intake. RF subjects reduced their reported fat intake during the study (P = 0.017) compared with RS and C subjects, and RS subjects reduced their reported sucrose intake compared with RF and C subjects (P = 0.049). Group differences in total sugar intake were not significantly different. All groups reported a small but significant increase in reported protein intake during the study, whereas there were no significant effects on percentage energy from total carbohydrate. Body weights did not change significantly in any group over the study period. These results indicate that, as a single dietary strategy, casual use of macronutrient-substituted foods by consumers under normal eating conditions can significantly influence the macronutrient composition of the diet, but has little net effect on total energy intake or body weight status.

Eating frequency: methodological and dietary aspects.

It is commonly stated that 'snack' foods provide 'empty calories' and, therefore elevate energy intake whilst providing insignificant quantities of other nutrients. The data presented in the present review suggest that foods which contribute to the pattern of 'snacking' contribute significantly to the nutrient quality of the diet. Those who 'snack' frequently tend to eat more food in general. Part of the difficulty in identifying the nutritional implications of 'snacking' is related to the definitions of 'meals' and 'snacks' and subsequent categorization of individual patterns. The physiological definitions typically relating to energy content or the time of eating do not necessarily coincide with colloquial, cultural or individual perceptions of what constitutes a 'meal' or 'snack'. Clearly, a more consistent approach would facilitate interpretation of the literature and enable more effective health education messages about 'snacking' to be delivered.

Relationships of consumer characteristics and food deprivation to food purchasing behavior.

A large part of domestic food intake may be determined by retail food purchase behavior, and it is commonly believed that this may be significantly influenced by the shopper's state of food deprivation. In the present study, 198 subjects recruited just prior to shopping at a large supermarket completed questionnaires eliciting information on demographic and situational variables, along with measures of time since last eating (TSLE), hunger, and dietary restraint. Upon leaving the store, subjects provided investigators with itemized receipts, having first identified all "unintended" purchases. There were no consistent main effects of TSLE, self-reported hunger, dietary restraint scores, or relative body weight on the number or cost of total, intended, and unintended food and nonfood purchases. However, there were significant interactions of weight status and measures of food deprivation upon measures of food purchasing. Although normal-weight subjects tended to increase their food purchases with food deprivation, the number and cost of food items fell markedly with extended food deprivation among overweight subjects. These effects were largely specific to food (i.e., generally not observed for nonfood purchases), but showed no consistent associations with unintended purchases or with particular foods or food groups. Higher dietary restraint and relative body weight were associated with lower reported hunger ratings, but not differences in mean TSLE, or other subject characteristics. These results run directly counter to common beliefs and recommendations for weight control and dieting, but support earlier work indicating that the food purchasing behaviors of normal-weight and overweight individuals are differently affected by food deprivation.

Effect of partially depolymerized guar gum on acute metabolic variables in patients with non-insulin-dependent diabetes.

Fourteen patients with non-insulin-dependent diabetes (NIDDM) attended the study centre on 4 mornings separated by at least 3 days, to receive in random order 75 g carbohydrate breakfast meals of control or guar breads with jam and butter. Guar gum flours of low, medium, and high molecular weight (MW) were incorporated into wheat bread rolls to provide 7.6 g guar per meal. Venous blood samples were taken via an indwelling cannula in a forearm vein at fasting and at eight postprandial times and then analysed for blood glucose, plasma insulin, C-peptide, and gastric inhibitory polypeptide (GIP). Guar gum bread significantly reduced the postprandial rise in blood glucose, plasma insulin, and, except for bread containing low MW guar gum, plasma GIP levels compared to the control. Thus, the partial depolymerization of guar gum does not diminish its physiological activity. No reductions in postprandial plasma C-peptide levels were seen after any of the guar bread meals. This suggests that guar gum attenuates the insulin concentration in peripheral venous blood in patients with NIDDM by increasing the hepatic extraction of insulin.

Nutritional implications of reduced-fat food use by free-living consumers.

The nutritional implications of the purchase and consumption of reduced-fat foods at home were assessed in normal-weight, free-living consumers in a 6-week intervention study. Control (n = 14) and experimental (n = 15) subjects kept 4-day weighed food diaries to establish energy and macronutrient intake at baseline and experimental weeks 2, 4 and 6. The control group continued their habitual diet throughout the study whereas the experimental group used reduced-fat foods ad libitum in place of the traditionally high-fat counterparts that they usually consumed. All subjects purchased the majority of their groceries from the same food store and were reimbursed for a proportion of their grocery bill. Repeated-measures analysis of variance indicated that the experimental group, compared to the control group, significantly reduced their percentage of energy from fat (from 38.3 +/- 1.8 to 30.4 +/- 1.7), but increased the percentage of energy from protein (p = 0.06) and carbohydrate (p = 0.019) such that changes in total energy intake were not statistically significantly different between conditions. Nevertheless, the experimental group lost 1.1 kg (while the control group gained 0.4 kg) in the first 4 weeks of the study, consistent with the observed reduction in energy intake, though no further body weight changes were seen in week 6. This study suggests that although use of reduced-fat foods may have short-term effects on energy balance, long-term sustained reduction in energy intake may be limited if this dietary strategy is used in isolation.

Impairment of cognitive performance associated with dieting and high levels of dietary restraint.

Seventy women students were tested on a short battery of tasks assessing cognitive performance. They also completed self-report ratings of mood, the Dutch Eating Behaviour Questionnaire (DEBQ) to which was appended several additional items concerning their recent dieting behaviour, and a 24-h dietary recall. Heart rate was measured before and after testing. Compared with nondieting subjects with low to moderate scores on the restraint factor of the DEBQ, subjects (n = 15) who reported that they were currently dieting to lose weight displayed impaired performance on a vigilance task and also tended to show poorer immediate memory and longer reaction times. Highly restrained eaters who were not dieting at the time of testing, on the whole, performed at an intermediate level on these tests. In contrast, the dieters tended to show the best performance on an undemanding finger tapping task, indicating that they were not slowed in their fine motor responses or lacking in motivation to carry out the tasks. Poorer cognitive functioning during dieting could arise as a direct consequence of the effects of food restriction on energy metabolism or other physiological mechanisms--the dietary records indicated that the current dieters were eating at about 70% of maintenance energy requirement. However, it is also possible that cognitive performance is impaired during dieting due to anxiety resulting from stressful effects of imposing and maintaining dietary restraint.

A positive change for a healthier life: Weight reduction strategies for obese people.

People who are obese have increased risk of a range of conditions, and also often suffer socially and psychologically. To successfully reduce their weight, they need to make lifelong changes in their eating and exercise habits.

Maintenance of pregnancy in Crohn's disease by parenteral nutrition: a case study.

This case report illustrates the nutritional difficulties which may be encountered in pregnancy in a Crohn's disease patient who has undergone extensive gut resection. It also highlights the possible application of supplementary parenteral feeding to maintain adequate growth in fetuses small for gestational age because of maternal nutritional deprivation.