Modification of appetite by bread consumption: A systematic review of randomized controlled trials

The Influence of Various Types of Functional Bread on Postprandial Glycemia in Healthy Adults

Bread is a crucial component of a balanced diet. Increasing the choice of functional bakery products based on whole grain flours, with the addition of seeds and grains, can improve health, including reducing postprandial glycemia and the risk of metabolic syndrome. The current study attempted to characterize the relationship between the composition and nutritional value of 23 different types of functional bread and postprandial glycemic response values. This study involved 209 non-obese healthy volunteers aged between 18 and 50. The study protocol followed the standard glycemic index (GI) method outlined by the International Standard, ISO 26642:2010. Most of the examined bread had a low GI and was composed mainly of rye, oats, buckwheat flour with a sourdough starter, and oilseeds. Postprandial glycemia was negatively associated with the fat, protein, and fiber content of bread. However, the GI depended directly on the carbohydrate content and, inversely, on the fat content in wheat bread and bread containing oilseeds. Similarly, using whole-grain flour and sourdough in a functional bakery reduces the GI. Adding oilseeds and sourdough to bread also reduced blood glucose levels approximately one hour after a meal. A greater number of ingredients in a recipe may be associated with a higher GI. In designing a functional bread with a potentially beneficial effect on postprandial glycemia, the nutritional value, type of fermentation, and additives (type and number) are worth considering. The high variability in postprandial glycemia after bread consumption is related to several factors and requires GI determination according to standard methods to ensure that the information provided to the consumer is reliable.

The nutritional contribution and relationship with health of bread consumption: a narrative review

Bread consumption dates back thousands of years, being one of the oldest and most widespread staple food worldwide. While bread is often associated with taste, pleasure, and tradition, its perception as a vehicle of nutrition and health remains complex. Today, there is no scientific consensus on whether bread consumption is beneficial or deleterious to human health. The objective of this review is therefore to present and discuss epidemiological and clinical evidence on the nutritional contribution of bread and its relationship with health. We also present different aspects of bread such as flour type and inclusions that may modulate this relationship. Studies included in this review investigate bread as part of a dietary pattern as well as the effect of bread alone on overweight, cardiometabolic health, and digestive health. Bread is an integral part of diets around the world, with a significant contribution to key nutrients. Although evidence on the impact of bread consumption on health is still lacking and depends on the overall diet, whole grain breads have shown consistent beneficial effects on human health. Substitution modeling studies and well-designed clinical trials are warranted to fill the research gaps and understand the role of bread consumption in health and disease.

Predicting the properties of wheat flour from grains during debranning: A machine learning approach

In the food industry, meeting food quality demands is challenging. The quality of wheat flour, one of the most commonly used ingredients, depends on the extent of debranning done to remove the aleurone layer before milling. Therefore, the end product management can be simplified by predicting the properties of wheat flour during the debranning stage. Therefore, the chemical and rheological properties of grains were analyzed at different debranning durations (0, 30, 60 s). Then the images of wheat grain were taken to develop a regression model for predicting the chemical quality (i.e., ash, starch, fat, and protein contents) of the wheat flour. The resulting regression model comprises a convolutional neural network and is evaluated using the coefficient of determination (R 2), root-mean-square error, and mean absolute error as metrics. The results demonstrated that wheat flour contained more fat and protein and less ash with increasing debranning time. The model proved reliable in terms of root-mean-square error, mean absolute error, and R 2 for predicting ash content but not starch, fat, or protein contents, which can be attributed to the lack of features in the collected images of wheat kernels during debranning. In addition, the selected method, debranning, was beneficial to the rheological characteristics of wheat flour. The proportion of fine particles increased with the debranning time. The study experimentally revealed that the end product diversity for wheat flour can be controlled to provide selectable ingredients to customers.

Positive contribution of hydroxytyrosol-enriched wheat bread to HbA1c levels, lipid profile, markers of inflammation and body weight in subjects with overweight/obesity and type 2 diabetes mellitus

PURPOSE

The aim of the present study was to assess the impact of the daily consumption of bread enriched with hydroxytyrosol on HbA₁c and blood lipid levels, inflammatory markers and weight loss.

METHODS

Sixty adults with overweight/obesity and type 2 diabetes mellitus (29 male, 31 female) participated in a 12-week dietary intervention based on the Mediterranean diet and consumed daily 60 g of conventional whole wheat bread (WWB) or whole wheat bread enriched with hydroxytyrosol (HTB). Anthropometric characteristics were measured and venous blood samples were collected at baseline and at the end of the intervention.

RESULTS

Both groups experienced significant weight loss, body fat and waist circumference decrease (p < 0.001). Nonetheless, a greater body fat mass decrease was observed in the HTB group compared to the WWB group (14.4 ± 1.6 vs 10.2 ± 1.1%, p = 0.038). Significant reductions were also reported in fasting glucose, HbA₁c and blood pressure in both groups (p < 0.05). Regarding glucose and HbA₁c, greater decreases were observed in the intervention group (101.4 ± 19.9 vs. 123.2 ± 43.4 mg/dL, p = 0.015 and 6.0 ± 0.6 vs. 6.4 ± 0.9%, p = 0.093, respectively). At HTB group, significant reductions in blood lipid, insulin, TNF-αand adiponectin levels (p < 0.05) and a marginally significant reduction in leptin levels (p = 0.081) were also reported.

CONCLUSION

Enrichment of bread with HT resulted in significant body fat mass reduction and positive effects on fasting glucose, insulin and HbA₁c levels. It also contributed to reductions in inflammatory markers and blood lipid levels. Incorporation of HT in staple foods, like bread, may improve their nutritional profile and, in terms of a balanced diet, may contribute to the management of chronic diseases.

TRIAL REGISTRATION

The study was prospectively registered in clinicaltrials.gov (24th May 2021).

CLINICALTRIALS

gov Identifier: NCT04899791.

Impact of a Low-Insulin-Stimulating Bread on Weight Development-A Real Life Randomised Controlled Trial

The impact on body weight development is usually analysed by comparing different diet types. Our approach was to change only one component, namely bread, common to most diets. In a single-centre triple-blind randomised controlled trial the effects of two different breads on body weight were analyzed without further lifestyle modification. Overweight adult volunteers (n = 80) were randomised 1:1 to exchange previously consumed breads for either a rye bread from milled whole grain (control) or a medium-carbohydrate, low-insulin-stimulating bread (intervention). Pre-tests demonstrated that the two bread types strongly differed in the glucose and insulin response elicited, but had similar energy content, texture and taste. The primary endpoint was the estimated treatment difference (ETD) in change of body weight after 3 months of treatment. Whereas body weight remained unchanged in the control group (-0.1 ± 2.0 kg), significant weight reduction was observed in the intervention group (-1.8 ± 2.9 kg), with an ETD of -1.7 ± 0.2 kg (p = 0.007), that was more pronounced in participants ≥ 55 years (-2.6 ± 3.3 kg), paralleled by significant reductions in body mass index and hip circumference. Moreover, in the intervention group, the percentage of participants with significant weight loss (≥1 kg) was twice as high as in the control group (p < 0.001). No other statistically significant changes in clinical or lifestyle parameters were noted. Simply exchanging a common insulinogenic bread for a low-insulin-stimulating bread demonstrates potential to induce weight loss in overweight persons, especially those at older age.

Nutritional benefits of sourdoughs: A systematic review

Food fermentation using sourdough-i.e., consortia of lactic bacteria and yeasts-is increasingly considered among the public as a natural transformation yielding nutritional benefits; however, it is unclear whether its alleged properties are validated by science. The aim of this study was to systematically review the clinical evidence related to the effect of sourdough bread on health. Bibliographic searches were performed in 2 different databases (The Lens and PubMed) up to February 2022. Eligible studies were randomized controlled trials involving adults, healthy or not, given any type of sourdough bread compared with those given any type of yeast bread. A total of 573 articles were retrieved and investigated, of which 25 clinical trials met the inclusion criteria. The 25 clinical trials included a total of 542 individuals. The main outcomes investigated in the retrieved studies were glucose response (N = 15), appetite (N = 3), gastrointestinal markers (N = 5), and cardiovascular markers (N = 2). Overall, it is currently difficult to establish a clear consensus with regards to the beneficial effects of sourdough per se on health when compared with other types of bread because a variety of factors, such as the microbial composition of sourdough, fermentation parameters, cereals, and flour types potentially influence the nutritional properties of bread. Nonetheless, in studies using specific strains and fermentation conditions, significant improvements were observed in parameters related to glycemic response, satiety, or gastrointestinal comfort after bread ingestion. The reviewed data suggest that sourdough has great potential to produce a variety of functional foods; however, its complex and dynamic ecosystem requires further standardization to conclude its clinical health benefits.

The influence of dough kneading time and flour particle size distribution on white bread structure, glycemic response and aspects of appetite

BACKGROUND & AIMS

White bread is widely consumed in many countries despite being a high-glycemic index (GI) food. It has been shown that the "food matrix effect" may help with diabetes and obesity management through lowering GI and appetite. This study aimed at investigating the effects of dough kneading time and flour particle size on white bread structure, glycemic response, and aspects of appetite.

METHODS

A two-phase randomized cross-over design was used in 10 healthy subjects over the course of 2 h. In phase 1, Texture Profile Analysis (TPA) attributes, Scanning Electron Microscope (SEM) image, glycemic response, and appetite aspects of white bread made with a 15-min dough kneading time (K15) were compared with white bread made with a 10-min dough kneading time (K10). In phase 2, TPA, SEM image, glycemic response, and satiety score of white bread made with coarse flour (CF) were compared to white bread made with fine flour (FF).

RESULT

With increasing hardness (force required to compress a food between the molars to a given deformation), total blood glucose IAUC in K15 (IAUC = 119 ± 12; GI = 66) was significantly (p < 0.05) lower than in K10 (IAUC = 154 ± 10; GI = 81). No marked difference was observed between K15 and K10 on aspects of appetite except for hunger. There was no significant (p > 0.05) difference in glycemic response between CF (IAUC = 126 ± 18; GI = 64) and FF (IAUC = 147 ± 12; GI = 81). Similarly, no discernible difference in satiety between CF and FF.

CONCLUSION

Changes in processing conditions can improve blood glucose response relalated to white bread consumption.

Glycaemic and Appetite Suppression Effect of a Vegetable-Enriched Bread

Bread, a frequently consumed food, is an ideal vehicle for addition of ingredients that increase nutrient density and add health benefits. This experimental cross-over study sought to test the effect of a vegetable-enriched bread (VB) in comparison to commercial white bread (WB) and wheatmeal bread (WMB) on serum glucose, insulin response and subjective appetite suppression. On three separate occasions, 10 participants (23 ± 7 years) visited the laboratory and consumed after an overnight fast, in random order, a 75 g serve of WB, WMB or VB. Venous blood samples drawn twice before (0 min) and at 15, 30, 45, 60, 90 and 120 min after consumption of the bread were analysed for glucose and insulin. Participants rated their subjective feelings of hunger, fullness, satisfaction and desire to eat on a 150 mm Likert scale. The mean glucose iAUC over 120 min was not different among the breads. The mean insulin iAUC for the VB was significantly lower than the WB and WMB; difference VB and WB 12,415 pmol/L*minutes (95% CI 1918, 22,912 pmol/L*minutes, p = 0.025) and difference VB and WMB 13,800 pmol/L*minutes (95% CI 1623, 25,976 pmol/L*minutes p = 0.031). The VB was associated with a higher fullness feeling in the participants over the 120-min period. The consumption of VB was associated with less insulin release and higher satiety over 120 min which may be related to the higher fibre content and texture of VB. The role of vegetable and fruit fibres such as pectin in bread and insulin response should also be further explored.

The functional food production: Application of stinging nettle leaves and its extracts in the baking of a bread

Stinging nettle is an annual plant. This plant is known for applications in folk medicine, and as the human diet. The stinging nettle leaves has been used to obtain extracts, which are expected to be with a high content of biologically active compounds. Prepared microwave extracts were applied in the formulation of the functional products. The article completes preparation of the bread with addition of the stinging nettle leaves and its extract, and bread's composition in phenolic acids, flavonoids, micro elements, and macro elements. The biological activity of the prepared bread samples showed significant antioxidant activity. This was especially true against DPPH radicals. It has been shown that it holds a high cytotoxic activity. Leaves themselves decreased the quality of the bread, while the extract improved the quality. It was sensorially confirmed. The article concluded that the extract substitutes leaves in bread as a product of a high benefit.

An empirical investigation of the impact of smoking on body weight using an endogenous treatment effects model approach: the role of food consumption patterns

BACKGROUND

This study explored the influence of cigarette smoking and food consumption patterns on BMI after adjusting for various socio-demographic characteristics. Since weight-based stereotypes may have an impact on smoking behaviour and both obesity and smoking have been associated with detrimental health effects, an interdependency between them is quite possible.

METHODS

Cross-sectional data were collected via a formal standardized questionnaire administered in personal interviews and two additional self-completion questionnaires from a random sample of 3471 German adults. The empirical framework considered potential endogeneity between smoking and body weight by employing an endogenous treatment effects model with an ordered outcome. The estimations derived from the endogenous treatment effects approach were also compared to the univariate ordered probit model results.

RESULTS

Our findings showed that ignoring potential endogeneity may affect both the statistical significance of the smoking estimate and the direction of the influence of smoking on BMI. Smoking was positively associated with BMI in both male (β = 1.236, p < 0.01) and female (β = 0.634, p < 0.10) participants. Smokers presented a 23.1% higher risk of obesity and a 24.3% lower likelihood of being within a healthy weight range. Male smokers also appeared to have a considerably augmented probability of being obese compared to their female counterparts (23.6% vs 15.1%). The relationship between smoking and BMI may be attributed to dietary practices, since smoking was correlated with poor dietary habits characterized by the frequent intake of more energy-dense foods (meat products and white-toasted bread) and less frequent consumption of healthy food items, such as whole-grain bread, vegetables and fruits. Concerning the impact of eating habits on body weight, frequent consumption of meat products and confectionery was found to have a direct association with BMI in both genders. Furthermore, white-toasted bread consumption was negatively linked with body weight in males (β = - 0.337, p < 0.01).

CONCLUSIONS

Our findings raised questions about the general belief that smoking is an effective weight control tool. Health interventions should be oriented toward a simultaneous decrease in smoking and obesity, since both behaviours seem to be interdependent. Nutrition programmes should also be designed according to the characteristics of different target groups in order to promote a healthy lifestyle.