Objectives
The National Institutes of Health, led by the National Heart, Lung, and Blood Institute, organized a working group of experts to discuss the problem of weight regain after weight loss. A ...number of experts in integrative physiology and behavioral psychology were convened with the goal of merging their perspectives regarding the barriers to scientific progress and the development of novel ways to improve long‐term outcomes in obesity therapeutics. The specific objectives of this working group were to: (1) identify the challenges that make maintaining a reduced weight so difficult; (2) review strategies that have been used to improve success in previous studies; and (3) recommend novel solutions that could be examined in future studies of long‐term weight control.
Results
Specific barriers to successful weight loss maintenance include poor adherence to behavioral regimens and physiological adaptations that promote weight regain. A better understanding of how these behavioral and physiological barriers are related, how they vary between individuals, and how they can be overcome will lead to the development of novel strategies with improved outcomes.
Conclusions
Greater collaboration and cross‐talk between physiological and behavioral researchers is needed to advance the science and develop better strategies for weight loss maintenance.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Obesity is a risk factor for hypertension, diabetes mellitus (DM), dyslipidemia, and hyperuricemia. Here, we evaluated whether the same body mass index (BMI) for the U.S. population conferred similar ...metabolic risk in Japan. This was a cross-sectional analysis involving 90,047 Japanese adults (18⁻85 years) from St. Luke's International Hospital, Tokyo, Japan and 14,734 adults from National Health and Nutrition Examination Survey (NHANES) collected in the U.S. We compared the prevalence of hypertension, DM, dyslipidemia, and hyperuricemia according to BMI in Japan and the U.S. The prevalence of hypertension, DM, and dyslipidemia were significantly higher in the U.S. than Japan, whereas the prevalence of hyperuricemia did not differ between countries. Higher BMI was an independent risk factor for hypertension, DM, dyslipidemia, and hyperuricemia both in Japan and in the U.S. after adjusting for age, sex, smoking and drinking habits, chronic kidney disease, and other cardiovascular risk factors. The BMI cut-off above which the prevalence of these cardio-metabolic risk factors increased was significantly higher in the U.S. than in Japan (27 vs. 23 kg/m² for hypertension, 29 vs. 23 kg/m² for DM, 26 vs. 22 kg/m² for dyslipidemia, and 27 vs. 23 kg/m² for hyperuricemia). Higher BMI is associated with an increased prevalence of hypertension, DM, dyslipidemia, and hyperuricemia both in Japan and U.S. The BMI cut-off above which the prevalence of cardio-metabolic risk factors increases is significantly lower in Japan than the U.S., suggesting that the same definition of overweight/obesity may not be similarly applicable in both countries.
Dietary guidelines for obesity typically focus on three food groups (carbohydrates, fat, and protein) and caloric restriction. Intake of noncaloric nutrients, such as salt, are rarely discussed. ...However, recently high salt intake has been reported to predict the development of obesity and insulin resistance. The mechanism for this effect is unknown. Here we show that high intake of salt activates the aldose reductase–fructokinase pathway in the liver and hypothalamus, leading to endogenous fructose production with the development of leptin resistance and hyperphagia that cause obesity, insulin resistance, and fatty liver. A high-salt diet was also found to predict the development of diabetes and nonalcoholic fatty liver disease in a healthy population. These studies provide insights into the pathogenesis of obesity and diabetes and raise the potential for reduction in salt intake as an additional interventional approach for reducing the risk for developing obesity and metabolic syndrome.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Biology's response to dieting: the impetus for weight regain MACLEAN, Paul S; BERGOUIGNAN, Audrey; CORNIER, Marc-Andre ...
American journal of physiology. Regulatory, integrative and comparative physiology,
09/2011, Volume:
301, Issue:
3
Journal Article
Peer reviewed
Open access
Dieting is the most common approach to losing weight for the majority of obese and overweight individuals. Restricting intake leads to weight loss in the short term, but, by itself, dieting has a ...relatively poor success rate for long-term weight reduction. Most obese people eventually regain the weight they have worked so hard to lose. Weight regain has emerged as one of the most significant obstacles for obesity therapeutics, undoubtedly perpetuating the epidemic of excess weight that now affects more than 60% of U.S. adults. In this review, we summarize the evidence of biology's role in the problem of weight regain. Biology's impact is first placed in context with other pressures known to affect body weight. Then, the biological adaptations to an energy-restricted, low-fat diet that are known to occur in the overweight and obese are reviewed, and an integrative picture of energy homeostasis after long-term weight reduction and during weight regain is presented. Finally, a novel model is proposed to explain the persistence of the "energy depletion" signal during the dynamic metabolic state of weight regain, when traditional adiposity signals no longer reflect stored energy in the periphery. The preponderance of evidence would suggest that the biological response to weight loss involves comprehensive, persistent, and redundant adaptations in energy homeostasis and that these adaptations underlie the high recidivism rate in obesity therapeutics. To be successful in the long term, our strategies for preventing weight regain may need to be just as comprehensive, persistent, and redundant, as the biological adaptations they are attempting to counter.
Objective
This review summarizes a portion of the discussions of an NIH Workshop (Bethesda, MD, 2015) titled “Self‐Regulation of Appetite—It's Complicated,” which focused on the biological aspects of ...appetite regulation.
Methods
This review summarizes the key biological inputs of appetite regulation and their implications for body weight regulation.
Results
These discussions offer an update of the long‐held, rigid perspective of an “adipocentric” biological control, taking a broader view that also includes important inputs from the digestive tract, from lean mass, and from the chemical sensory systems underlying taste and smell. It is only beginning to be understood how these biological systems are integrated and how this integrated input influences appetite and food eating behaviors. The relevance of these biological inputs was discussed primarily in the context of obesity and the problem of weight regain, touching on topics related to the biological predisposition for obesity and the impact that obesity treatments (dieting, exercise, bariatric surgery, etc.) might have on appetite and weight loss maintenance. Finally considered is a common theme that pervaded the workshop discussions, which was individual variability.
Conclusions
It is this individual variability in the predisposition for obesity and in the biological response to weight loss that makes the biological component of appetite regulation so complicated. When this individual biological variability is placed in the context of the diverse environmental and behavioral pressures that also influence food eating behaviors, it is easy to appreciate the daunting complexities that arise with the self‐regulation of appetite.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Objective
To evaluate the safety and tolerability of alternate‐day fasting (ADF) and to compare changes in weight, body composition, lipids, and insulin sensitivity index (Si) with those produced by ...a standard weight loss diet, moderate daily caloric restriction (CR).
Methods
Adults with obesity (BMI ≥30 kg/m2, age 18‐55) were randomized to either zero‐calorie ADF (n = 14) or CR (−400 kcal/day, n = 12) for 8 weeks. Outcomes were measured at the end of the 8‐week intervention and after 24 weeks of unsupervised follow‐up.
Results
No adverse effects were attributed to ADF, and 93% completed the 8‐week ADF protocol. At 8 weeks, ADF achieved a 376 kcal/day greater energy deficit; however, there were no significant between‐group differences in change in weight (mean ± SE; ADF −8.2 ± 0.9 kg, CR −7.1 ± 1.0 kg), body composition, lipids, or Si. After 24 weeks of unsupervised follow‐up, there were no significant differences in weight regain; however, changes from baseline in % fat mass and lean mass were more favorable in ADF.
Conclusions
ADF is a safe and tolerable approach to weight loss. ADF produced similar changes in weight, body composition, lipids, and Si at 8 weeks and did not appear to increase risk for weight regain 24 weeks after completing the intervention.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Interests in the impact of the gastrointestinal microbiota on health and wellbeing have extended from humans to that of companion animals. While relatively fewer studies to date have examined canine ...and feline gut microbiomes, analysis of the metagenomic DNA from fecal communities using next‐generation sequencing technologies have provided insights into the microbes that are present, their function, and potential to contribute to overall host nutrition and health. As carnivores, healthy dogs and cats possess fecal microbiomes that reflect the generally higher concentrations of protein and fat in their diets, relative to omnivores and herbivores. The phyla Firmicutes and Bacteroidetes are highly abundant, and Fusobacteria, Actinobacteria, and Proteobacteria also feature prominently. Proteobacteria is the most diverse bacterial phylum and commonly features in the fecal microbiota of healthy dogs and cats, although its reputation is often sullied as its members include a number of well‐known opportunistic pathogens, such as Escherichia coli, Salmonella, and Campylobacter, which may impact the health of the host and its owner. Furthermore, in other host species, high abundances of Proteobacteria have been associated with dysbiosis in hosts with metabolic or inflammatory disorders. In this review, we seek to gain further insight into the prevalence and roles of the Proteobacteria within the gastrointestinal microbiomes of healthy dogs and cats. We draw upon the growing number of metagenomic DNA sequence‐based studies which now allow us take a culture‐independent approach to examine the functions that this more minor, yet important, group contribute to normal microbiome function.
The fecal microbiomes of healthy dogs and cats often include Proteobacteria at varying abundances. This phylum can have a sullied reputation as it contains a number of well‐known pathogenic members. We explored the functions of the Proteobacteria in fecal shotgun metagenome datasets from healthy dogs and cats. The Proteobacteria appeared to be enriched for functions that are consistent with a role in helping to maintain the anaerobic environment of the gut for normal microbiome function.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
From an animal health perspective, our understanding of the metabolites in rumen fluid across different host species is poorly understood. Here, we present a metabolomic data set generated using ...hydrophilic interaction liquid chromatography and semi-polar (C18) chromatography methods coupled to high-resolution mass spectrometry of fractionated ovine rumen samples.
Obesity and its co-morbidities, such as fatty liver disease, are increasingly prevalent worldwide health problems. Intestinal microorganisms have emerged as critical factors linking diet to host ...physiology and metabolic function, particularly in the context of lipid homeostasis. We previously demonstrated that deletion of the cytoplasmic lipid drop (CLD) protein Perilipin-2 (Plin2) in mice largely abrogates long-term deleterious effects of a high fat (HF) diet. Here we test the hypotheses that Plin2 function impacts the earliest steps of HF diet-mediated pathogenesis as well as the dynamics of diet-associated changes in gut microbiome diversity and function. WT and perilipin-2 null mice raised on a standard chow diet were randomized to either low fat (LF) or HF diets. After four days, animals were assessed for changes in physiological (body weight, energy balance, and fecal triglyceride levels), histochemical (enterocyte CLD content), and fecal microbiome parameters. Plin2-null mice had significantly lower respiratory exchange ratios, diminished frequencies of enterocyte CLDs, and increased fecal triglyceride levels compared with WT mice. Microbiome analyses, employing both 16S rRNA profiling and metagenomic deep sequencing, indicated that dietary fat content and Plin2 genotype were significantly and independently associated with gut microbiome composition, diversity, and functional differences. These data demonstrate that Plin2 modulates rapid effects of diet on fecal lipid levels, enterocyte CLD contents, and fuel utilization properties of mice that correlate with structural and functional differences in their gut microbial communities. Collectively, the data provide evidence of Plin2 regulated intestinal lipid uptake, which contributes to rapid changes in the gut microbial communities implicated in diet-induced obesity.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Land-spreading of animal faecal wastes -such as animal beddings- can introduce zoonotic enteropathogens into the food system environment. The study evaluated the effectiveness of animal beddings ...naturally contaminated by calf manure to reduce E. coli O157:H7 or Salmonella enterica. The two pathogens were introduced separately as a four strains-cocktail and at high (>6.5 Log10 g-1) concentration into bedding materials, and their inactivation over a 10 weeks-period was monitored by using a Most Probable Number (MPN) enumeration method. Inactivation of E. coli O157:H7 was more effective in the bedding inoculated immediately after collection from calf pens than in the beddings inoculated after a 2 months-pre-storage period: E. coli O157:H7 levels were reduced by 6.6 Log10 g-1 in unstored bedding (0.5 Log10 g-1 recovered; 95%CI: 0.0-1.2), and by 4.9 Log10 g-1 in pre-stored bedding (2.2 Log10 g-1 recovered; 95%CI: 1.5-2.8) with a significant (p<0.05) difference between unstored and pre-stored. S. enterica was inactivated less effectively as counts were reduced by one order of magnitude, with no significant difference in inactivation between unstored and pre-stored beddings. Low levels of naturally occurring E. coli O157 and Salmonella spp. were detected in the non-inoculated beddings, as well as in the straw prior to use in the animal facility. To better understand the possible biological processes involved, the bacterial community present in the beddings was characterised by short-read 16S rRNA sequencing. Pre-storage of the bedding affected the composition but not the diversity of the bacterial community. Analyses of the key bacterial phyla suggested that the presence of a diverse and stable bacterial community might facilitate inactivation of the introduced pathogens, and a possible role of bacterial orders associated with lignocellulolytic resources. Overall, the study contributed to the understanding of the fate of zoonotic bacteria introduced in animal beddings during storage and identified bedding storage practices pre-and post-use in animal facilities that could be important to prevent the risk of zoonosis dissemination to the environment or to the dairy herds.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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