Principles and Practice of Structural Equation Modeling (2nd ed.)

Objective: The recent obesity epidemic has been accompanied by a parallel growth in chronic sleep deprivation. Physiologic studies suggest sleep deprivation may influence weight through effects on appetite, physical activity, and/or thermoregulation. This work reviews the literature regarding short sleep duration as an independent risk factor for obesity and weight gain.

Short sleep duration and weight gain : a systematic review

Background: Low-carbohydrate diets remain popular despite a paucity of scientific evidence on their effectiveness. Objective: To compare the effects of a low-carbohydrate, ketogenic diet program with those of a low-fat, low-cholesterol, reduced-calorie diet. Design: Randomized, controlled trial. Setting: Outpatient research clinic. Participants: 120 overweight, hyperlipidemic volunteers from the community. Intervention: Low-carbohydrate diet (initially, <20 g of carbohydrate daily) plus nutritional supplementation, exercise recommendation, and group meetings, or low-fat diet (<30% energy from fat, <300 mg of cholesterol daily, and deficit of 500 to 1000 kcal/d) plus exercise recommendation and group meetings. Measurements: Body weight, body composition, fasting serum lipid levels, and tolerability. Results: A greater proportion of the low-carbohydrate diet group than the low-fat diet group completed the study (76% vs. 57%; P= 0.02). At 24 weeks, weight loss was greater in the low-carbohydrate diet group than in the low-fat diet group (mean change, -12.9% vs. -6.7%; P < 0.001). Patients in both groups lost substantially more fat mass (change, -9.4 kg with the low-carbohydrate diet vs. -4.8 kg with the low-fat diet) than fat-free mass (change, -3.3 kg vs. -2.4 kg, respectively). Compared with recipients of the low-fat diet, recipients of the low-carbohydrate diet had greater decreases in serum triglyceride levels (change, -0.84 mmol/L vs. -0.31 mmol/L [-74.2 mg/dL vs. -27.9 mg/ dL]; P = 0.004) and greater increases in high-density lipoprotein cholesterol levels (0.14 mmol/L vs. -0.04 mmol/L [5.5 mg/dL vs. -1.6 mg/dL]; P< 0.001). Changes in low-density lipoprotein cholesterol level did not differ statistically (0.04 mmol/L [1.6 mg/dL] with the low-carbohydrate diet and -0.19 mmol/L [-7.4 mg/dL] with the low-fat diet; P = 0.2). Minor adverse effects were more frequent in the low-carbohydrate diet group. Limitations: We could not definitively distinguish effects of the low-carbohydrate diet and those of the nutritional supplements provided only to that group. In addition, participants were healthy and were followed for only 24 weeks. These factors limit the generalizability of the study results. Conclusions: Compared with a low-fat diet, a low-carbohydrate diet program had better participant retention and greater weight loss. During active weight loss, serum triglyceride levels decreased more and high-density lipoprotein cholesterol level increased more with the low-carbohydrate diet than with the low-fat diet.

A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial.

Fast foods are frequently linked to the epidemic of obesity, but there has been very little scientific appraisal of a possible causal role Here we review a series of studies demonstrating that the energy density of foods is a key determinant of energy intake These studies show that humans have a weak innate ability to recognise foods with a high energy density and to appropriately down-regulate the bulk of food eaten in order to maintain energy balance This induces so called 'passive over-consumption' Composition data from leading fast food company websites are then used to illustrate that most fast foods have an extremely high energy density At some typical outlets the average energy density of the entire menus is approximately 1100 kJ 100 g(-1) This is 65% higher than the average British diet (approximately 670 kJ 100 g(-1)) and more than twice the energy density of recommended healthy diets (approximately 525 kJ 100 g(-1)) It is 145% higher than traditional African diets (approximately 450 kJ 100 g(-1)) that probably represent the levels against which human weight regulatory mechanisms have evolved We conclude that the high energy densities of many fast foods challenge human appetite control systems with conditions for which they were never designed Among regular consumers they are likely to result in the accidental consumption of excess energy and hence to promote weight gain and obesity

/pdf/fast-foods-energy-density-and-obesity-a-possible-mechanistic-2l9awj3xqx.pdf

Fast foods, energy density and obesity: a possible mechanistic link.

http://ernaehrungsdenkwerkstatt.de/fileadmin/user_upload/EDWText/TextElemente/Ernaehrungswissenschaft/Naehrstoffe/Saettigung_Biomarker_deGraaf_AJCN_79_946_2004.pdf

Biomarkers of satiation and satiety

Studies of the value of compassion on physical and mental health and social relationships have proliferated in the last 25 years. Although, there are several conceptualisations and measures of compassion, this study develops three new measures of compassion competencies derived from an evolutionary, motivational approach. The scales assess 1. the compassion we experience for others, 2. the compassion we experience from others, and 3. self-compassion based on a standard definition of compassion as a ‘sensitivity to suffering in self and others with a commitment to try to alleviate and prevent it’. We explored these in relationship to other compassion scales, self-criticism, depression, anxiety, stress and well-being. Participants from three different countries (UK, Portugal and USA) completed a range of scales including compassion for others, self-compassion, self-criticism, shame, depression, anxiety and stress with the newly developed ‘The Compassionate Engagement and Actions’ scale. All three scales have good validity. Interestingly, we found that the three orientations of compassion are only moderately correlated to one another (r < .5). We also found that some elements of self-compassion (e.g., being sensitive to, and moved by one’s suffering) have a complex relationship with other attributes of compassion (e.g., empathy), and with depression, anxiety and stress. A path-analysis showed that self-compassion is a significant mediator of the association between self-reassurance and well-being, while self-criticism has a direct effect on depressive symptoms, not mediated by self-compassion. Compassion evolved from caring motivation and in humans is associated with a range of different socially intelligent competencies. Understanding how these competencies can be inhibited and facilitated is an important research endeavour. These new scales were designed to assess these competencies. This is the first study to measure the three orientations of compassion derived from an evolutionary model of caring motivation with specified competencies. Our three new measures of compassion further indicate important complex relationships between different potentiation’s of compassion, well-being, and vulnerability to psychopathologies.

/pdf/the-development-of-compassionate-engagement-and-action-3qjp8mfuu4.pdf

The development of compassionate engagement and action scales for self and others

This article examines the importance of dietary energy density (ED) as a major factor that may influence human appetite and energy intake (EI). The article examines whether the effects of diet composition on appetite and EI can be explained in terms of ED. There is clear evidence that dietary macronutrients exert differential effects on energy intake (EI), both in the laboratory and in real life. Under normal conditions where fat contributes disproportionately to ED, protein, carbohydrate, and fat exert hierarchical effects on satiety in the order protein >carbohydrate > fat. Alcohol appears to stimulate EI. In human appetite studies the main effect of controlling ED is to diminish the impact of differences in the satiating effects of fat and carbohydrate. ED exerts profound effects in constraining EI in short-to-medium term studies. Subjects behave differently in longer term interventions. In short-to-medium term laboratory studies, increases in ED are more effective at increasing EI than at decreasing food intake. In longer term and cross-sectional studies conducted in naturalistic environments, increased ED appears more effective at decreasing food intake and less effective at elevating EI. The available evidence suggests that we should be evolving more complex, multifactor models to account for the observations that both macronutrients and ED affect EI rather than substituting one simplistic model with another.

Energy density of foods: effects on energy intake.

Objective To determine the accuracy of wrist and arm-worn activity monitors’ estimates of energy expenditure (EE) Data sources SportDISCUS (EBSCOHost), PubMed, MEDLINE (Ovid), PsycINFO (EBSCOHost), Embase (Ovid) and CINAHL (EBSCOHost) Design A random effects meta-analysis was performed to evaluate the difference in EE estimates between activity monitors and criterion measurements Moderator analyses were conducted to determine the benefit of additional sensors and to compare the accuracy of devices used for research purposes with commercially available devices Eligibility criteria We included studies validating EE estimates from wrist-worn or arm-worn activity monitors against criterion measures (indirect calorimetry, room calorimeters and doubly labelled water) in healthy adult populations Results 60 studies (104 effect sizes) were included in the meta-analysis Devices showed variable accuracy depending on activity type Large and significant heterogeneity was observed for many devices (I2 >75%) Combining heart rate or heat sensing technology with accelerometry decreased the error in most activity types Research-grade devices were statistically more accurate for comparisons of total EE but less accurate than commercial devices during ambulatory activity and sedentary tasks Conclusions EE estimates from wrist and arm-worn devices differ in accuracy depending on activity type Addition of physiological sensors improves estimates of EE, and research-grade devices are superior for total EE These data highlight the need to improve estimates of EE from wearable devices, and one way this can be achieved is with the addition of heart rate to accelerometry PROSPEROregistration number CRD42018085016

https://bjsm.bmj.com/content/bjsports/54/6/332.full.pdf

How well do activity monitors estimate energy expenditure? A systematic review and meta-analysis of the validity of current technologies

This handbook is a comprehensive collection of measures and assessment tools intended for use by researchers and clinicians that work with people with problem eating behaviors, obese clients, and the associated psychological issues that underlie these problems. It is a reference for researchers who specialize in obesity research and individuals that specialize in working with clients with problem eating behaviors and how to measure and assess their attitudes, beliefs and behaviors with regard to food. It is much broader than eating disorders as it deals with obesity (an area that has reached epidemic proportions in the US) and problem eating behaviors. Its collection is truly unique as no other volume offers such a comprehensive collection all in one place dealing with and focusing on assessments and measures related to eating behaviours. The assessment tools included in this volume include:

- General Personality Assessment and psychopathology of persons with eating and weight related concerns 

- Measures of quality of life assessments 

- Methods for measuring attitudes and beliefs about obese people 

- Assessment of Body Image 

- Measures of Restrained Eating 

- Measures of Physical Activity 

- Measuring Food Intake 

- Binge Eating and Purging 

- Assessment of Eating and Weight related problems with Children 

- Identification of Psychological Problems of patients with eating disorders.

Measuring food intake, hunger, satiety and satiation in the laboratory

Energy balance can be estimated in tissues, body segments, individual subjects (the focus of the present article), groups of subjects and even societies. Changes in body composition in individual subjects can be translated into changes in the energy content of the body, but this method is limited by the precision of the techniques. The precision for measuring fat and fat-free mass can be as low as 0.5 kg when certain reference techniques are used (hydrodensitometry, air-displacement plethysmography, dual-energy X-ray absorptiometry), and approximately 0.7 kg for changes between two time points. Techniques associated with a measurement error of 0.7 kg for changes in fat and fat-free mass (approximately 18MJ) are of little or no value for calculating energy balance over short periods of time, but they may be of some value over long periods of time (18 MJ over I year corresponds to an average daily energy balance of 70 kJ, which is 5-10 kg. The same principles can be applied to the assessment of energy balance in body segments using dual-energy X-ray absorptiometry. Energy balance can be obtained over periods as short as a few minutes, e.g. during measurements of BMR. The variability in BMR between individuals of similar age, weight and height and gender is about 7-9 %, most of which is of biological origin rather than measurement error, which is about 2 %. Measurement of total energy expenditure during starvation (no energy intake) can also be used to estimate energy balance in a whole-body calorimeter, in patients in intensive care units being artificially ventilated and by tracer techniques. The precision of these techniques varies from 1 to 10 %. Establishing energy balance by measuring the discrepancy between energy intake and expenditure has to take into consideration the combined validity and reliability of both components. The measurement error for dietary intake may be as low as 2-3 % in carefully controlled environments, in which subjects are provided only with certain food items and bomb calorimetry can be undertaken on duplicate samples of the diet. Reliable results can also be obtained in hospitalised patients receiving enteral tube feeding or parenteral nutrition as the only source of nutrition. Unreliability increases to an unknown extent in free-living subjects eating a mixed and varied diet; thus, improved methodology is needed for the study of energy balance.

/pdf/techniques-for-the-study-of-energy-balance-in-man-h7of9911f1.pdf

James Stubbs

Papers

The development of compassionate engagement and action scales for self and others

Energy density of foods: effects on energy intake.

How well do activity monitors estimate energy expenditure? A systematic review and meta-analysis of the validity of current technologies

Measuring food intake, hunger, satiety and satiation in the laboratory

Techniques for the study of energy balance in man.