The intent of this paper is to address the obesity epidemic, which is a term used to describe the sudden and rapid increase in obesity rates that began in the 1980s and continues unabated today. ...Since 1980, the entire population, regardless of starting weight, is gradually gaining weight. This has led to escalating obesity rates and to obesity being considered one of the most serious public health challenges facing the world. At one level, the obesity epidemic is a classic gene-environment interaction where the human genotype is susceptible to environmental influences that affect energy intake and energy expenditure. It is also a problem of energy balance. Understanding the etiology of obesity requires the study of how behavioral and environmental factors have interacted to produce positive energy balance and weight gain. Reversing the epidemic of obesity will require modifying some combination of these factors to help the population achieve energy balance at a healthy body weight. While body weight is strongly influenced by biological and behavioral factors, changes in the environment promoting positive energy balance have been most responsible for the obesity epidemic. Our best strategy for reversing the obesity epidemic is to focus on preventing positive energy balance in the population through small changes in diet and physical activity that take advantage of our biological systems for regulating energy balance. Simultaneously, we must address the environment to make it easier to make better food and physical activity choices. This is a very long-term strategy for first stopping and then reversing the escalating obesity rates, but one that can, over time, return obesity rates to pre-1980s levels.
The continued rise in obesity rates in most countries suggests that current programs and initiatives designed to combat obesity have not been successful in reversing the obesity epidemic. Obesity ...rates are increasing because of a gradual weight gain in most populations. There has been little long-term success in treating established obesity through lifestyle change, perhaps because of the large permanent changes in diet and physical activity required to keep weight off. An alternative strategy to address the obesity epidemic involves not focusing on weight loss but promoting small changes in diet and physical activity to initially prevent further weight gain. With the use of this strategy, obesity rates could first be stabilized in most populations and then, over time, decrease gradually. Supporting data show that small reductions in conscious energy intake and increases in physical activity can reduce excessive weight gain. The opportunity exists to use the small-changes approach to bring different stakeholders together to create a national initiative to address the global epidemic of obesity. The Joint Task Force of the American Society for Nutrition, Institute of Food Technologists, and International Food Information Council believe that a small-changes framework, aimed at helping people make conscious small changes in lifestyle behaviors, in combination with efforts by the private sector to gradually “ratchet down” some of the environmental factors that have contributed to excessive energy intake and the declining rates of physical activity, can be successful in reducing obesity rates. Such an initiative would benefit from the support of educational and social marketing campaigns developed with governmental input and support.
Energy Balance and Obesity HILL, James O; WYATT, Holly R; PETERS, John C
Circulation,
07/2012, Letnik:
126, Številka:
1
Journal Article
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This paper describes the interplay among energy intake, energy expenditure and body energy stores and illustrates how an understanding of energy balance can help develop strategies to reduce obesity. ...First, reducing obesity will require modifying both energy intake and energy expenditure and not simply focusing on either alone. Food restriction alone will not be effective in reducing obesity if human physiology is biased toward achieving energy balance at a high energy flux (i.e. at a high level of energy intake and expenditure). In previous environments a high energy flux was achieved with a high level of physical activity but in today's sedentary environment it is increasingly achieved through weight gain. Matching energy intake to a high level of energy expenditure will likely be more a more feasible strategy for most people to maintain a healthy weight than restricting food intake to meet a low level of energy expenditure. Second, from an energy balance point of view we are likely to be more successful in preventing excessive weight gain than in treating obesity. This is because the energy balance system shows much stronger opposition to weight loss than to weight gain. While large behavior changes are needed to produce and maintain reductions in body weight, small behavior changes may be sufficient to prevent excessive weight gain. In conclusion, the concept of energy balance combined with an understanding of how the body achieves balance may be a useful framework in helping develop strategies to reduce obesity rates.
Background The challenge of weight-loss maintenance is well known, but few studies have followed successful weight losers over an extended period or evaluated the effect of behavior change on weight ...trajectories. Purpose To study the weight-loss trajectories of successful weight losers in the National Weight Control Registry (NWCR) over a 10-year period, and to evaluate the effect of behavior change on weight-loss trajectories. Methods A 10-year observational study of self-reported weight loss and behavior change in 2886 participants (78% female; mean age 48 years) in the NWCR who at entry had lost at least 30 lbs (13.6 kg) and kept it off for at least one year. Data were collected in 1993–2010; analysis was conducted in 2012. Main outcome measures Weight loss (kilograms; percent weight loss from maximum weight). Results Mean weight loss was 31.3 kg (95% CI=30.8, 31.9) at baseline, 23.8 kg (95% CI=23.2, 24.4) at 5 years and 23.1±0.4 kg (95% CI=22.3, 23.9) at 10 years. More than 87% of participants were estimated to be still maintaining at least a 10% weight loss at Years 5 and 10. Larger initial weight losses and longer duration of maintenance were associated with better long-term outcomes. Decreases in leisure-time physical activity, dietary restraint, and frequency of self-weighing and increases in percentage of energy intake from fat and disinhibition were associated with greater weight regain. Conclusions The majority of weight lost by NWCR members is maintained over 10 years. Long-term weight-loss maintenance is possible and requires sustained behavior change.
The recommendation to limit dietary saturated fatty acid (SFA) intake has persisted despite mounting evidence to the contrary. Most recent meta-analyses of randomized trials and observational studies ...found no beneficial effects of reducing SFA intake on cardiovascular disease (CVD) and total mortality, and instead found protective effects against stroke. Although SFAs increase low-density lipoprotein (LDL) cholesterol, in most individuals, this is not due to increasing levels of small, dense LDL particles, but rather larger LDL particles, which are much less strongly related to CVD risk. It is also apparent that the health effects of foods cannot be predicted by their content in any nutrient group without considering the overall macronutrient distribution. Whole-fat dairy, unprocessed meat, and dark chocolate are SFA-rich foods with a complex matrix that are not associated with increased risk of CVD. The totality of available evidence does not support further limiting the intake of such foods.
This paper presents two inter-dependent frameworks for understanding the etiology of obesity and the regain of body and fat mass after weight loss. The ‘Invisible Hand of Metabolism’ illustrates how ...physiologic states such as body and fat mass and blood glucose levels arise from the unregulated, uncontrolled, yet competitive behavior of trillions of semi-autonomous cells. The ‘Competition Model of Metabolism’ is an explanatory (mechanistic) framework that details how organismal and cell-specific behaviors generate the apparent stability of physiologic states despite metabolic perturbations (e.g., weight-loss and exercise). Together, these frameworks show that body and fat mass and blood glucose levels are not regulated, controlled, or defended but emerge from the complexity and functional plasticity of competitive cellular relations. Therefore, we argue that the use of abstract constructs such as ‘regulation’, ‘control’, ‘glucostats’, ‘adipostats’, and ‘set−/settling-points’ hinders the understanding of obesity and cardiometabolic diseases in human and nonhuman mammals.
The existence of metabolic adaptation, at the level of resting metabolic rate (RMR), remains highly controversial, likely due to lack of standardization of participants’ energy balance. Moreover, its ...role as a driver of relapse remains unproven.
The main aim was to determine if metabolic adaptation at the level of RMR was present after weight loss and at 1- and 2-y follow-up, with measurements taken under condition of weight stability. A secondary aim was to investigate race differences in metabolic adaptation after weight loss and if this phenomenon was associated with weight regain.
A total of 171 overweight women BMI (kg/m2): 28.3 ± 1.3; age: 35.2 ± 6.3 y; 88 whites and 83 blacks enrolled in a weight-loss program to achieve a BMI <25, and were followed for 2 y. Body weight and composition (4-compartment model) and RMR (indirect calorimetry) were measured after 4 wk of weight stability at baseline, after weight loss and at 1 and 2 y. Metabolic adaptation was defined as a significantly lower measured compared with predicted RMR (from own regression model).
Participants lost, on average, 12 ± 2.6 kg and regained 52% ± 38% and 89% ± 54% of their initial weight lost at 1 and 2 y follow-up, respectively. Metabolic adaptation was found after weight loss (−54 ± 105 kcal/d; P < 0.001), with no difference between races and was positively correlated with fat-mass loss, but not with weight regain, overall. In a subset of women (n = 46) with data at all time points, metabolic adaptation was present after weight loss, but not at 1- or 2-y follow-up (−43 ± 119, P = 0.019; −18 ± 134, P = 0.380; and − 19 ± 166, P = 0.438 kcal/day respectively).
In overweight women, metabolic adaptation at the level of RMR is minimal when measurements are taken under conditions of weight stability and does not predict weight regain up to 2 years follow-up. The JULIET study is registered at https://clinicaltrials.gov/ct2/show/NCT00067873 as NCT00067873.
During the past several decades, numerous trials have compared various diets for the management of overweight and obesity, assuming that a single dietary strategy would be appropriate for all ...individuals. These studies have failed to provide strong evidence for the efficacy of any particular diet, and it is likely that different people will have different levels of success on different diets. We identified studies investigating pretreatment glycemia or insulinemia status, or both, of the individual as prognostic markers of weight loss during periods in which the composition of a participant's diet was known. Overall, research suggests that providing specific diets for weight management based on pretreatment glycemia and insulinemia statuses holds great promise for advancing personalized nutrition.
Background: The prevalence of obesity in the United States has increased dramatically.
Objective: The aim of this study was to determine trends in carbohydrate, fat, and protein intakes in adults and ...their association with energy intake by using data from the National Health and Nutrition Examination Survey (NHANES)—a representative sample of the US population.
Design: Data on adults aged 20–74 y from the first NHANES (NHANES I, 1971–1975; n = 13,106) were compared with data from NHANES 2005–2006 (n = 4381). Normal weight was defined as a body mass index (BMI; in kg/m2) of 19 to <25, overweight as a BMI of 25 to <30, and obese as a BMI of ≥30. Carbohydrate, fat, and protein intakes were obtained by dietary recall. Regression analyses were adjusted for potential confounders.
Results: The prevalence of obesity increased from 11.9% to 33.4% in men and from 16.6% to 36.5% in women. The percentage of energy from carbohydrates increased from 44.0% to 48.7%, the percentage of energy from fat decreased from 36.6% to 33.7%, and the percentage of energy from protein decreased from 16.5% to 15.7%. Trends were identical across normal-weight, overweight, and obese groups. Energy intake increased substantially in all 3 BMI groups. In NHANES 2005–2006, a 1% increase in the percentage of energy from protein was associated with a decrease in energy intake of 32 kcal (substituted for carbohydrates) or 51 kcal (substituted for fat). Similar findings were seen across all BMI categories, in men and women, and in NHANES I.
Conclusions: Energy intake and the prevalence of obesity have increased dramatically. Dietary interventions should focus on decreasing energy intake and potentially by substituting protein for fat or carbohydrates.
Background: Breakfast is associated with lower body weight in observational studies. Public health authorities commonly recommend breakfast consumption to reduce obesity, but the effectiveness of ...adopting these recommendations for reducing body weight is unknown.Objective: We tested the relative effectiveness of a recommendation to eat or skip breakfast on weight loss in adults trying to lose weight in a free-living setting. Design: We conducted a multisite, 16-wk, 3-parallel-arm randomized controlled trial in otherwise healthy overweight and obese adults body mass index (in kg/m2) between 25 and 40 aged 20–65 y. Our primary outcome was weight change. We compared weight change in a control group with weight loss in experimental groups told to eat breakfast or to skip breakfast no breakfast (NB). Randomization was stratified by prerandomization breakfast eating habits. A total of 309 participants were randomly assigned.Results: A total of 283 of the 309 participants who were randomly assigned completed the intervention. Treatment assignment did not have a significant effect on weight loss, and there was no interaction between initial breakfast eating status and treatment. Among skippers, mean (±SD) baseline weight-, age-, sex-, site-, and race-adjusted weight changes were −0.71 ± 1.16, −0.76 ± 1.26, and −0.61 ± 1.18 kg for the control, breakfast, and NB groups, respectively. Among breakfast consumers, mean (±SD) baseline weight-, age-, sex-, site-, and race-adjusted weight changes were −0.53 ± 1.16, −0.59 ± 1.06, and −0.71 ± 1.17 kg for the control, breakfast, and NB groups, respectively. Self-reported compliance with the recommendation was 93.6% for the breakfast group and 92.4% for the NB group.Conclusions: A recommendation to eat or skip breakfast for weight loss was effective at changing self-reported breakfast eating habits, but contrary to widely espoused views this had no discernable effect on weight loss in free-living adults who were attempting to lose weight. This trial was registered at clinicaltrails.gov as NCT01781780.
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