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Critical Care Clinics Jan 2018Sepsis is characterized by early massive catabolism, lean body mass (LBM) loss, and escalating hypermetabolism persisting for months to years. Early enteral nutrition... (Review)
Review
Sepsis is characterized by early massive catabolism, lean body mass (LBM) loss, and escalating hypermetabolism persisting for months to years. Early enteral nutrition should attempt to correct micronutrient/vitamin deficiencies, deliver adequate protein and moderated nonprotein calories, as well-nourished patients can generate reasonable endogenous energy. After resuscitation, increasing protein/calories are needed to attenuate LBM loss and promote recovery. Malnutrition screening is essential, and parenteral nutrition can be safely added when enteral nutrition is failing based on preillness malnutrition. Following discharge from intensive care unit, significantly increased protein/calorie delivery is required for months to years to facilitate functional and LBM recovery.
Topics: Critical Care; Critical Illness; Enteral Nutrition; Humans; Nutritional Support; Parenteral Nutrition; Practice Guidelines as Topic; Sepsis
PubMed: 29149933
DOI: 10.1016/j.ccc.2017.08.008 -
GeroScience Jun 2021The global human population has recently experienced an increase in life expectancy with a mounting concern about the steady rise in the incidence of age-associated... (Review)
Review
The global human population has recently experienced an increase in life expectancy with a mounting concern about the steady rise in the incidence of age-associated chronic diseases and socio-economic burden. Calorie restriction (CR), the reduction of energy intake without malnutrition, is a dietary manipulation that can increase health and longevity in most model organisms. However, the practice of CR in day-to-day life is a challenging long-term goal for human intervention. Recently, daily fasting length and periodicity have emerged as potential drivers behind CR's beneficial health effects. Numerous strategies and eating patterns have been successfully developed to recapitulate many of CR's benefits without its austerity. These novel feeding protocols range from shortened meal timing designed to interact with our circadian system (e.g., daily time-restricted feeding) to more extended fasting regimens known as intermittent fasting. Here, we provide a glimpse of the current status of knowledge on different strategies to reap the benefits of CR on metabolic health in murine models and in humans, without the rigor of continuous reduction in caloric intake as presented at the USU State of the Science Symposium.
Topics: Animals; Caloric Restriction; Diet; Energy Intake; Fasting; Feeding Behavior; Humans; Mice
PubMed: 33686571
DOI: 10.1007/s11357-021-00335-z -
American Journal of Physiology.... Nov 2017One of the central tenets in obesity prevention and management is caloric restriction. This perspective presents salient features of how calories and energy balance...
One of the central tenets in obesity prevention and management is caloric restriction. This perspective presents salient features of how calories and energy balance matter, also called the "calories in, calories out" paradigm. Determinants of energy balance and relationships to dietary macronutrient content are reviewed. The rationale and features of the carbohydrate-insulin hypothesis postulate that carbohydrate restriction confers a metabolic advantage. According to this model, a large amount of fat intake is enabled without weight gain. Evidence concerning this possibility is detailed. The relationship and application of the laws of thermodynamics are then clarified with current primary research. Strong data indicate that energy balance is not materially changed during isocaloric substitution of dietary fats for carbohydrates. Results from a number of sources refute both the theory and effectiveness of the carbohydrate-insulin hypothesis. Instead, risk for obesity is primarily determined by total calorie intake.
Topics: Caloric Restriction; Diabetes Mellitus, Type 2; Diet; Dietary Carbohydrates; Dietary Fats; Eating; Energy Intake; Energy Metabolism; Humans; Insulin; Obesity; Weight Gain
PubMed: 28765272
DOI: 10.1152/ajpendo.00156.2017 -
Cell Metabolism Oct 2022Morning loaded calorie intake in humans has been advocated as a dietary strategy to improve weight loss. This is also supported by animal studies suggesting time of... (Randomized Controlled Trial)
Randomized Controlled Trial
Morning loaded calorie intake in humans has been advocated as a dietary strategy to improve weight loss. This is also supported by animal studies suggesting time of eating can prevent weight gain. However, the underlying mechanisms through which timing of eating could promote weight loss in humans are unclear. In a randomized crossover trial (NCT03305237), 30 subjects with obesity/overweight underwent two 4-week calorie-restricted but isoenergetic weight loss diets, with morning loaded or evening loaded calories (45%:35%:20% versus 20%:35%:45% calories at breakfast, lunch, and dinner, respectively). We demonstrate no differences in total daily energy expenditure or resting metabolic rate related to the timing of calorie distribution, and no difference in weight loss. Participants consuming the morning loaded diet reported significantly lower hunger. Thus, morning loaded intake (big breakfast) may assist with compliance to weight loss regime through a greater suppression of appetite.
Topics: Animals; Appetite; Diet, Reducing; Energy Intake; Energy Metabolism; Healthy Volunteers; Humans; Hunger; Obesity; Weight Loss
PubMed: 36087576
DOI: 10.1016/j.cmet.2022.08.001 -
Recent Results in Cancer Research.... 2016Cancer is the second leading cause of death in the USA and among the leading major diseases in the world. It is anticipated to continue to increase because of the growth... (Review)
Review
Cancer is the second leading cause of death in the USA and among the leading major diseases in the world. It is anticipated to continue to increase because of the growth of the aging population and prevalence of risk factors such as obesity, smoking, and/or poor dietary habits. Cancer treatment has remained relatively similar during the past 30 years with chemotherapy and/or radiotherapy in combination with surgery remaining the standard therapies although novel therapies are slowly replacing or complementing the standard ones. According to the American Cancer Society, the dietary recommendation for cancer patients receiving chemotherapy is to increase calorie and protein intake. In addition, there are no clear guidelines on the type of nutrition that could have a major impact on cancer incidence. Yet, various forms of reduced caloric intake such as calorie restriction (CR) or fasting demonstrate a wide range of beneficial effects able to help prevent malignancies and increase the efficacy of cancer therapies. Whereas chronic CR provides both beneficial and detrimental effects as well as major compliance challenges, periodic fasting (PF), fasting-mimicking diets (FMDs), and dietary restriction (DR) without a reduction in calories are emerging as interventions with the potential to be widely used to prevent and treat cancer. Here, we review preclinical and preliminary clinical studies on dietary restriction and fasting and their role in inducing cellular protection and chemotherapy resistance.
Topics: Caloric Restriction; Diet; Fasting; Humans; Neoplasms; United States
PubMed: 27557543
DOI: 10.1007/978-3-319-42118-6_12 -
JAMA Internal Medicine Aug 2018Despite intensive research, the causes of the obesity epidemic remain incompletely understood and conventional calorie-restricted diets continue to lack long-term... (Review)
Review
Despite intensive research, the causes of the obesity epidemic remain incompletely understood and conventional calorie-restricted diets continue to lack long-term efficacy. According to the carbohydrate-insulin model (CIM) of obesity, recent increases in the consumption of processed, high-glycemic-load carbohydrates produce hormonal changes that promote calorie deposition in adipose tissue, exacerbate hunger, and lower energy expenditure. Basic and genetic research provides mechanistic evidence in support of the CIM. In animals, dietary composition has been clearly demonstrated to affect metabolism and body composition, independently of calorie intake, consistent with CIM predictions. Meta-analyses of behavioral trials report greater weight loss with reduced-glycemic load vs low-fat diets, though these studies characteristically suffer from poor long-term compliance. Feeding studies have lacked the rigor and duration to test the CIM, but the longest such studies tend to show metabolic advantages for low-glycemic load vs low-fat diets. Beyond the type and amount of carbohydrate consumed, the CIM provides a conceptual framework for understanding how many dietary and nondietary exposures might alter hormones, metabolism, and adipocyte biology in ways that could predispose to obesity. Pending definitive studies, the principles of a low-glycemic load diet offer a practical alternative to the conventional focus on dietary fat and calorie restriction.
Topics: Animals; Caloric Restriction; Dietary Carbohydrates; Energy Intake; Energy Metabolism; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Obesity
PubMed: 29971406
DOI: 10.1001/jamainternmed.2018.2933 -
American Journal of Lifestyle Medicine 2020What does the best available balance of scientific evidence show is the optimum way to lose weight? Calorie density, water content, protein source, and other components... (Review)
Review
What does the best available balance of scientific evidence show is the optimum way to lose weight? Calorie density, water content, protein source, and other components significantly influence the effectiveness of different dietary regimes for weight loss. By "walling off your calories," preferentially deriving your macronutrients from structurally intact plant foods, some calories remain trapped within indigestible cell walls, which then blunts the glycemic impact, activates the ileal brake, and delivers prebiotics to the gut microbiome. This may help explain why the current evidence indicates that a whole food, plant-based diet achieves greater weight loss compared with other dietary interventions that do not restrict calories or mandate exercise. So, the most effective diet for weight loss appears to be the only diet shown to reverse heart disease in the majority of patients. Plant-based diets have also been found to help treat, arrest, and reverse other leading chronic diseases such as type 2 diabetes and hypertension, whereas low-carbohydrate diets have been found to impair artery function and worsen heart disease, the leading killer of men and women in the United States. A diet centered on whole plant foods appears to be a safe, simple, sustainable solution to the obesity epidemic.
PubMed: 32922235
DOI: 10.1177/1559827620912400 -
The International Journal of Eating... Mar 2016Given the importance of weight restoration for recovery in patients with anorexia nervosa (AN), we examined approaches to refeeding in adolescents and adults across... (Review)
Review
OBJECTIVE
Given the importance of weight restoration for recovery in patients with anorexia nervosa (AN), we examined approaches to refeeding in adolescents and adults across treatment settings.
METHODS
Systematic review of PubMed, PsycINFO, Scopus, and Clinical Trials databases (1960-2015) using terms refeeding, weight restoration, hypophosphatemia, anorexia nervosa, anorexia, and anorexic.
RESULTS
Of 948 screened abstracts, 27 met these inclusion criteria: participants had AN; reproducible refeeding approach; weight gain, hypophosphatemia or cognitive/behavioral outcomes. Twenty-six studies (96%) were observational/prospective or retrospective and performed in hospital. Twelve studies published since 2010 examined approaches starting with higher calories than currently recommended (≥1400 kcal/d). The evidence supports 8 conclusions: 1) In mildly and moderately malnourished patients, lower calorie refeeding is too conservative; 2) Both meal-based approaches or combined nasogastric+meals can administer higher calories; 3) Higher calorie refeeding has not been associated with increased risk for the refeeding syndrome under close medical monitoring with electrolyte correction; 4) In severely malnourished inpatients, there is insufficient evidence to change the current standard of care; 5) Parenteral nutrition is not recommended; 6) Nutrient compositions within recommended ranges are appropriate; 7) More research is needed in non-hospital settings; 8) The long-term impact of different approaches is unknown;
DISCUSSION
Findings support higher calorie approaches to refeeding in mildly and moderately malnourished patients under close medical monitoring, however the safety, long-term outcomes, and feasibility outside of hospital have not been established. Further research is also needed on refeeding approaches in severely malnourished patients, methods of delivery, nutrient compositions and treatment settings.
Topics: Anorexia Nervosa; Female; Humans; Male; Parenteral Nutrition; Prospective Studies; Refeeding Syndrome; Retrospective Studies
PubMed: 26661289
DOI: 10.1002/eat.22482 -
Advances in Physiology Education Sep 2021Exercise is thought to be an effective means to quick weight loss. However, few people have realistic exercise-induced weight loss expectations. Fewer understand how...
Exercise is thought to be an effective means to quick weight loss. However, few people have realistic exercise-induced weight loss expectations. Fewer understand how weight is "lost" and where the lost mass goes. Understanding that fat is "burned" with inhaled oxygen and most of the mass lost must be exhaled as carbon dioxide might help individuals create realistic weight loss expectations. The purpose of this laboratory activity is to ) provide students with a basic understanding of the role of oxygen in fuel metabolism during physical activity and its relationship to energy expenditure and mechanical work, and ) engage students with collection of their own data to determine a realistic timeframe for exercise-induced weight loss. In the prelaboratory, questions such as, "When you lose weight, where does it go?" are asked. A guided discussion helps students understand the basic biochemistry required for weight loss. For the activity, students complete walking or running exercise, recording the time and distance. The relationship of exercise to physics' concepts of mechanical work and energy utilization are discussed with the concept of "calorie burn" and its relationship to oxygen consumption. Students estimate oxygen consumed and calories burned during exercise using established metabolic equations. Finally, the amount of energy (i.e., calories) equivalent to 1 pound of fat is discussed. Students calculate how long he/she would have to exercise to burn 10 pounds (4.5 kg) of fat. A person of average size and fitness, needs 60+ h of exercise to burn 10 pounds of fat. Supplementary activities including a dramatic gummy bear oxidation and the use of a metabolic cart reinforces these concepts and validates the laboratory estimates.
Topics: Energy Metabolism; Female; Humans; Laboratories; Male; Obesity; Oxygen Consumption; Weight Loss
PubMed: 34379483
DOI: 10.1152/advan.00006.2021