Meal replacement as a weight loss strategy for night shift workers with obesity: a protocol for a randomized controlled trial

BACKGROUND

Shift work is considered a risk factor for a number of chronic health conditions including obesity. Weight reduction in obese patients lowers the risk for cardiovascular disease, diabetes, certain cancers, and mortality. Achieving a negative energy balance by providing low-calorie meal replacements is widely used for weight management. This study aims to evaluate the impact of a low-calorie "meal-replacement" on the weight and metabolic parameters of shift workers with obesity.

METHODS

This trial will be conducted in a parallel, randomized controlled design for a period of 8 weeks. A total of 44 shift workers with body mass index over 25 kg/m² will be recruited after assessing eligibility. Participants will be randomly assigned to the test and control groups on a 1:1 ratio. The intervention group (N = 22) will be provided with a low-calorie (~200 kcal) meal replacement shake as dinner, and the control group (N = 22) will continue their habitual diets. The visits and the evaluations will be done as follows: screening (visit 0), 4 weeks (visit 1), and 8 weeks (visit 2). Anthropometric measurements will be taken at 0, 4, and 8 weeks. Body composition, biochemical parameters, dietary intake, and physical activity will be assessed during the first and the last visit.

OUTCOMES

The primary outcome will be the proportion of participants that had a 5% body weight loss from baseline. The secondary outcomes will be post-intervention changes in other metabolic parameters.

DISCUSSION

To our knowledge, this is one of the first randomized controlled trials evaluating the effects of a meal replacement as the night meal for weight loss in shift workers with obesity. Moreover, improvement of metabolic parameters in shift workers will be an added benefit to this high-risk group.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12622000231741 . Registered on 09 February 2022.

The Effect of Meal Replacement on Weight Loss According to Calorie-Restriction Type and Proportion of Energy Intake: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Portion control is a useful component of weight reduction interventions and meal replacement (MR) plans represent a promising strategy for portion control. Research performed with pooled data on the effect of MR plans according to various characteristics of MR interventions remains scarce.

OBJECTIVE

Our aim was to assess the effects of MR-based diets compared with food-based diets on weight loss, according to calorie-restriction types and energy intake proportions from MR.

METHODS

Electronic databases (Cochrane Central Register of Controlled Trials, PubMed, Embase, and Research Information Sharing Service) were searched for randomized controlled trials on weight loss results of MR-based calorie-restricted diets compared with food-based calorie-restricted diets from January 2000 to May 2020. Standardized mean differences (Hedges' g) from all study outcomes were calculated using a random-effects model. Heterogeneity was quantified by Q test and I². Publication bias was assessed using a funnel plot and a trim and fill method. Both interventions (MR and control) were separated into very-low-energy diets and low-energy diets (LEDs). A meta-analysis of variance was conducted by dividing patient-related factors and treatment-related factors into subgroups. In multivariable meta-regressions, background variables were selected first, after which main independent variables were included.

RESULTS

Twenty-two studies involving 24 interventions and 1,982 patients who were overweight or obese were included. The effect size in which MR-based LED was compared with food-based LED for weight loss was small, favoring MR (Hedges' g = 0.261; 95% CI 0.156 to 0.365; I² = 21.9; 95% CI 0.0 to 53.6). Diets including ≥60% of total daily energy intake from MR had a medium effect size favoring MR with regard to weight loss among the groups (Hedges' g = 0.545; 95% CI 0.260 to 0.830; I² = 42.7; 95% CI 0.0 to 80.8).

CONCLUSIONS

The effect of MR-based LED on weight loss was superior to the effect of food-based LED, and receiving ≥60% of total daily energy intake from MR had the greatest effect on weight loss.

Meal replacement in dietary management of type-2 diabetes mellitus: a scoping review protocol

BACKGROUND

The prevalence of type-2 diabetes mellitus (T2DM) has been increasing globally. Without proper management, T2DM can develop into serious complications and even death. Diet modification is one of the most effective tools in managing T2DM at the early stage, but it requires knowledge and compliance from the patients. Thus, meal replacement (MR) has gained its popularity as a tool for diet modification to improve glycemic control and also reducing weight in T2DM patients. There are several existing meal replacement studies but not much is known on the general scope and effect of these existing MRs. Hence, this review is aimed to provide an overview of the existing evidences regarding the application of meal replacement on T2DM patients and identify the gaps or limitations in the studies.

METHODOLOGY

The scoping review will be carried out in six stages: (1) identifying the research question, (2) identifying relevant studies through electronic databases (i.e., PubMed, Scopus, Cochrane Reviews, Google Scholar, EBSCOHOST, Science Direct) and also gray literature, and (3) selection of studies to be included based on inclusion criteria. Search and initial screening of studies to be included will be conducted by two independent reviewers. Discrepancies will then be solved through discussion with other reviewers; (4) charting and categorizing extracted data in a pretested data extraction form; (5) collating, summarizing, and reporting the results; and lastly, (6) conducting consultation with stakeholders and experts in diabetes.

DISCUSSION

This scoping review protocol is aimed to provide a framework enabling us to map and summarize the findings from existing studies involving meal replacement. It will help researchers to identify the research gap and provide recommendations for future meal replacement studies. The results from this scoping review will be useful to various stakeholders in healthcare. It is also part of a research project in which the information obtained will be utilized in a clinical trial of a developed meal replacement plan. Dissemination of knowledge will also be done through presentations at related scientific conferences.

Meal replacement in isolated and confined mission environments: Consumption, acceptability, and implications for physical and behavioral health

Strategies that reduce food system mass without negatively impacting food intake, acceptability, and resulting astronaut health and performance are essential for mission success in extreme operational environments such as space exploration. Here, we report the impact of substituting the spaceflight standard breakfast with energy equivalent, calorically-dense meal replacement bars (MRBs) on consumption, acceptability, and satiety and on associations with physical and behavioral health outcomes in high-performing subjects completing 30-day missions in the isolated and confined operational environment of NASA's Human Exploration Research Analog (HERA) habitat. MRB implementation was associated with reduced daily caloric intake, weight loss, and decrements in mood and neurobehavioral functioning, with no significant impacts on somatic symptoms and physical functioning. Food acceptability ratings suggest that flavor, texture, and menu fatigue attributed to limited variety are contributing factors, which are exacerbated by a daily implementation schedule. Meal replacement strategies for short-duration missions are operationally feasible, moderately acceptable, and can contribute to the practical goal of mass reduction, but more work is needed to define and optimize flavors, variety, and implementation schedules that sustain adequate nutrition, physical and behavioral health, and operational performance over time in isolated, confined, and extreme mission environments.

Visceral fat reduction is positively associated with blood pressure reduction in overweight or obese males but not females: an observational study

BACKGROUND

Visceral adiposity has been reported to play a key role in hypertension compared with other measurements of regional or general obesity. The aim of current study was to evaluate the relationship between visceral fat reduction and changes in blood pressure in a group of overweight or obese Chinese individuals.

METHODS

An observational study was conducted with 168 participants (ChiCTR-OOC-17012000). Body composition, blood parameters and blood pressure were assessed at the beginning and end of the intervention. Males and females were categorized separately into quartiles according to changes in visceral fat during the intervention. Multiple linear regression models were used to assess the associations of changes in systolic and diastolic blood pressure with changes of visceral fat area, adjusted for potential confounders.

RESULTS

Changes in visceral fat was significantly associated with systolic and diastolic blood pressure in men for systolic (β = 0.234, 95% CI: 0.103, 0.365; p = 0.001) and diastolic blood pressure (β = 0.237; 95% CI: 0.127, 0.346; p <0.001), but not in women after adjustment for the same potential confounders for systolic blood (β = - 0.003, 95% CI: - 0.260, 0.255; p = 0.984) and diastolic blood pressure (β = 0.101, 95% CI: - 0.072, 0.273; p = 0.249).

CONCLUSIONS

A positive association was observed between reduction in visceral fat and improvements in both systolic blood and diastolic blood pressures in males but not females in a 12-week meal replacement intervention.

TRIAL REGISTRATION

The Ethics Committee of Peking University Health Science Center approved the study protocol on 6 July 2017. The authors confirm that all ongoing and related trials for this intervention were carried out following the rules of the Declaration of Helsinki of 1975 and registered (ChiCTR-OOC-17012000). http://www.chictr.org.cn/showprojen.aspx?proj=20426.

Long-Term Weight-Loss Maintenance by a Meal Replacement Based Weight Management Program in Primary Care

OBJECTIVE

Structured obesity treatment programs at primary care level are becoming increasingly important. However, evidence from current treatment approaches in the long term is lacking. In view of this fact we evaluated a standardized, meal replacement-based weight loss program (myLINE®; AENGUS, Graz, Austria) according to the currently applicable guidelines.

METHODS

Data of overweight and obese individuals (n = 70) who participated at least 36 months in the program were analyzed. Data were collected at baseline (T0) as well as after 1, 3, 6, 12, 24, and 36 (T1-T36) months. Body composition was measured by conventional anthropometry and bioelectrical impedance analysis.

RESULTS

Compared to T0, a maximum weight, BMI, fat mass, absolute body cell mass (BCM) reduction and an increase of relative BCM could be seen at T6. Subsequently, the findings reveal a significant reduction of body weight and body fat and a satisfying development of body cell mass during the observation period of 36 months.

CONCLUSION

The evaluated program complies with national and international guidelines for the therapy of obesity in adults and is efficient and meaningful for a long-term therapeutic use in primary care..

A randomized controlled trial to determine the efficacy of a high carbohydrate and high protein ready-to-eat food product for weight loss

Incorporating meal replacements has been shown to produce a significantly greater weight loss than a conventional reduced calorie diet. Ready-to-eat conventional foods may also be effective in this role and provide additional benefit because of their palatability, acceptance and enjoyment and thus increase dietary compliance. This trial investigated the efficacy of a ready-to-eat food product (Vita-Weat biscuit) that is both high in carbohydrate and high in protein as part of a diet prescription for weight loss in an overweight and obese population group. A total of 76 participants were randomized to a 6-week weight loss intervention including the ready-to-eat food product (intervention group) or advice on the 'Australian Guide to Healthy Eating' (control group). Both groups lost approximately 2 kg weight which equated to a reduction in body mass index of 0.70 kg m(-2) . There was no significant difference in percentage weight loss from screening to 6 weeks between the two groups; mean difference for the intervention vs.

CONTROL GROUP

-0.20% (95% confidence interval: -0.96, 1.36); P = 0.73. Both diets were nutritionally matched and well-accepted over the 6-week period. This study shows that the inclusion of a ready-to-eat food product can be included as part of a dietary programme to achieve a clinically significant weight loss over a short period. This may have benefit when incorporated into an individual's meal plan intermittently to assist weight control. It also provides support for current public health nutritional guidelines as the participants in this study following such advice were also successful in achieving a clinically meaningful weight loss.

Consumer perceptions of satiating and meal replacement bars, built up from cues in packaging information, health claims and nutritional claims

Previous research has shown that consumers' sensory and hedonic perceptions could be greatly influenced by the messages highlighted on the front of the packaging, particularly nutrition and health claims for reduced-calorie or functional foods. In food products designed for hunger control, mentioning satiating effects or meal replacement could potentially influence the expected satiety or other perceptions, including those associated with a filling effect. This study investigated the effect of packaging information on consumer perceptions of eleven commercial chocolate-flavoured satiating and meal replacement bars. Projective mapping (Napping®) with a descriptive step was used to profile the expectations elicited by the eleven bars, based on their extrinsic characteristics (without tasting them), with two different groups of consumers in two different scenarios: mapping the samples' packaging and mapping cards with an identical design showing the most important information displayed on the packaging (product name, nutrition information panel and nutrition and health messages or claims). The terms and comments obtained in the two scenarios were analysed and perceptual spaces were generated from the sample location and attributes obtained in the Napping® exercises, using multi factor analysis (MFA). The results showed that when evaluating the real packaging, the consumers mainly focused on the meal replacement- or satiation-related messages and on the images to build up their perception, attaching less or no importance to the nutritional information that was also displayed on the box. When examining the packaging, sensory expectations - which probably emerged from the images of the bars - were also a very important factor in placing the samples in the perceptual space. When looking only at the cards, the consumers' grouping and attribute generation focused in great detail on the nutritional information. The calorie content also became a much more important factor in their perceptions of the bars. Interestingly for the product category analysed, messages about "satiating" and "meal replacement" effects were clearly distinct and negatively correlated in the consumers' minds.