Sweeteners and health: findings from recent research and their impact on obesity and related metabolic conditions.

Few topics in nutrition engender more controversy than added sugars in general, and fructose-containing sugars in particular. Some investigators have argued that added sugars are associated with increased risk of obesity, cardiovascular disease, diabetes, non-alcoholic fatty liver disease and even sugar 'addiction'. Other investigators have questioned the scientific basis for all of these assertions. This debate has extended far beyond the scientific community into various media outlets including the internet and other non-refereed venues often with heated rhetoric and little science. Against this backdrop, a group of experts and researchers in the metabolism and health effects of added sugars presented a symposium 'Sweeteners and Health: Findings from Recent Research and their Impact on Obesity and Related Metabolic Conditions' at the European Congress on Obesity on 7 May 2015. The papers in this supplement are based on the presentations made at this meeting. The current article is intended to serve as an Introduction to this supplement.

Added sugars and risk factors for obesity, diabetes and heart disease.

The effects of added sugars on various chronic conditions are highly controversial. Some investigators have argued that added sugars increase the risk of obesity, diabetes and cardiovascular disease. However, few randomized controlled trials are available to support these assertions. The literature is further complicated by animal studies, as well as studies which compare pure fructose to pure glucose (neither of which is consumed to any appreciable degree in the human diet) and studies where large doses of added sugars beyond normal levels of human consumption have been administered. Various scientific and public health organizations have offered disparate recommendations for upper limits of added sugar. In this article, we will review recent randomized controlled trials and prospective cohort studies. We conclude that the normal added sugars in the human diet (for example, sucrose, high-fructose corn syrup and isoglucose) when consumed within the normal range of normal human consumption or substituted isoenergetically for other carbohydrates, do not appear to cause a unique risk of obesity, diabetes or cardiovascular disease.

The reliability of isokinetic and isometric leg strength measures among individuals with symptoms of mild osteoarthritis.

AIM: The aim of the study is to evaluate the test-retest reliability of measures of isokinetic and isometric leg strength and joint function among individuals exhibiting symptoms of mild osteoarthritis. Reliable procedures are needed to assess the effectiveness of an intervention on osteoarthritic symptoms. METHODS: Test-retest reliability of two leg strength protocols was assessed using the intraclass correlation coefficient (R). Testing was completed on two occasions separated by 7 days. Eighteen subjects (9 male and 9 female; 54.1+/-11 years) completed an isokinetic testing trial, which consisted of a set of 5 maximal repetitions of the quadriceps and hamstrings at 60 deg/s followed by a set of 15 maximal contractions at 180 deg/s with a 2-min rest between sets and an isometric testing trial, which consist of 3 maximal contractions of the quadriceps for 6 s with a 30-s rest between contractions at 30, 45, and 80 degrees of knee flexion for a total of 9 isometric contractions. A 90-s rest occurred between angles. RESULTS: Most of the isokinetic variables showed moderate to high intraclass reliability (ICC). Two of the calculated isokinetic variables (work fatigue at 180 degrees /s for extension and for flexion) showed low intraclass reliability (ICC=0.78, resp. ICC=0.6). All calculated ICC values of the isometric variables were moderate to high. CONCLUSIONS: Test-retest reliability of isokinetic and isometric leg strength was high, allowing the intervention protocol to monitor changes in leg strength and joint function among those exhibiting symptoms of mild osteoarthritis.

Physician involvement in the management of obesity as a primary medical condition.

As the obesity epidemic escalates, increasing numbers of patients present with serious comorbidities related to excess body weight. Obesity should be recognized and treated as a primary medical condition that is progressive, chronic, and relapsing. Effective treatment of obesity has been shown to reduce cardiovascular risk factors and comorbid conditions. Physician involvement is necessary for medical assessment, management, counseling, and coordination of multidisciplinary obesity treatment. Obese patients who receive counseling and weight management from physicians are significantly more likely to undertake weight management programs than those who do not. Obesity treatment guidelines and materials are available from various health organizations. A comprehensive weight management program must include dietary adjustments, increased physical activity, and behavioral modification. Nutritional modifications should take into account the diet's energy content, composition, and suitability for the individual patient. The physical activity component should be safe and practical, including aerobic activity, strength training, and increased daily lifestyle activities. Various behavioral strategies enable the patient to make lifestyle changes that will promote weight loss and management. Adjunct therapies may serve to support lifestyle modifications in severe or resistant cases of obesity. Models for multidisciplinary care vary depending on whether they are designed for an individual medical practice or as part of the health care services of a larger facility. Lifestyle changes for healthy weight management must be permanently incorporated into a patient's daily lifestyle to reduce obesity and its associated health risks. Such intervention is necessary if the growing epidemic of obesity is to be slowed and reversed.

Obesity and cardiovascular disease risk: research update.

The obesity epidemic has reached unprecedented proportions in Western society. Evidence continues to accumulate that obesity is associated with significant morbidity and mortality and in particular that it is an independent risk factor for cardiovascular disease (CVD). The association of obesity with CVD and its risk factors, including hypertension, dyslipidemia, glucose intolerance, and impaired hemostasis is becoming more clearly understood. An increasing body of data indicates that risk factors tend to cluster in obese individuals and may act synergistically to increase these people's risk for CVD. Individuals with disproportionate visceral adiposity are at significantly greater risk for CVD. Adult weight gain also underlies the development of many risk factors and augments the risk of CVD. Physicians can play a vital and active role in the prevention and treatment of obesity and overweight and thereby reduce patients' CVD risk.

Obesity as a chronic disease: modern medical and lifestyle management.

The United States is in the midst of an epidemic of obesity involving more than one third of the adult population. The prevalence of obesity increased by 40% between 1980 and 1990. Obesity is a chronic disease with a multifactorial etiology including genetics, environment, metabolism, lifestyle, and behavioral components. A chronic disease treatment model involving both lifestyle interventions and, when appropriate, additional medical therapies delivered by an interdisciplinary team including physicians, dietitians, exercise specialists, and behavior therapists offers the best chance for effective obesity treatment. Lifestyle factors such as proper nutrition, regular physical activity, and changes in eating behaviors should be coordinated by this team. This review addresses the modern epidemic of obesity, the strong association between obesity and comorbidities such as coronary heart disease, type 2 diabetes, hypertension, and dyslipidemia. In addition to obesity, the health risks of abdominal obesity and adult weight gain are discussed. The evidence that supports health benefits from modest weight loss (between 5% and 10% of body weight) is evaluated and the 5 key principles of effective obesity therapy are put forward. Obesity is a therapeutic challenge best met by teams of health care professionals, including dietitians and physicians, working together to deliver optimal treatment.

The role of physical activity in the prevention and management of obesity.

The United States is facing 2 major lifestyle-related epidemics that are intricately linked: an epidemic of obesity and an epidemic of inactivity. Multiple interactions exist between lack of physical activity and obesity. Increased physical activity lowers the risk of obesity, may favorably influence distribution of body weight, and confers a variety of health-related benefits even in the absence of weight loss. Physical activity is important for achieving proper energy balance, which is needed to prevent or reverse obesity. Not only is energy expended during physical activity, physical activity also has a positive effect on resting metabolic rate. Regular physical activity can improve body composition. Properly designed programs of physical activity may preserve or even increase lean muscle mass during weight loss. Physical activity has also been strongly associated with maintenance of weight loss. Physical activity that expends 1,500 to 2,000 kcal/week appears necessary to maintain weight loss. Numerous studies have shown that the combination of proper nutrition and regular physical activity is the most effective intervention for weight loss and maintenance of weight loss. Walking is the most convenient and logical way most obese persons can increase their physical activity. Physical activity plays multiple roles in the prevention and treatment of obesity. Dietitians and other health care workers who treat obese patients should understand the role physical activity plays in comprehensive obesity treatment as well as how to incorporate a physical activity prescription in treatment plans for obese clients.

Improved psychological well-being, quality of life, and health practices in moderately overweight women participating in a 12-week structured weight loss program.

OBJECTIVE: To study the effects of a 12-week weight loss strategy involving increased physical activity, self-selected hypocaloric diet, and group support on psychological well-being, quality of life, and health practices in moderately obese women. METHODS: Eighty women aged 20-49 years weighing between 20-50% above 1983 Metropolitan Life Insurance Tables were randomly assigned to a weight loss intervention (6279 kJ/week of physical activity, 33,258-41,462 kJ/week diet and weekly meetings) or served as controls. Subjects were tested pre and post 12-weeks. RESULTS: The intervention group lost significant (p<0.001) body weight (kg) and body fat (%) compared to controls (-6.07+/-4.01 kg vs. 1.31+/-1.28 kg; 36.8%-32.5% vs. 36.2%-36.0%). Intervention subjects vs. controls achieved significant improvements (p<0.001) in body cathexis (X Change 18.6+/-16.7 vs. 0.7+/-8.6) and estimation of ability to achieve physical fitness (X Change 8.1+/-7.1 vs. 0.9+/-5.9). Various quality of life indices also improved (p<0.01) in the intervention group compared to controls (physical function: X Change 13.5.2+/-16.7 vs. 1.4+/-9.5; vitality: X change 21.7+/-17.9 vs. 2.9+/-20.8; mental health: X change 10.4+/-16.0 vs. 2.3+/-10.1). Similarly, physical activity levels also improved significantly (p<0.0001) in the intervention group (4.4+/-2.3 vs. 0.6+/-1.3; on NASA 0-7 scale). CONCLUSIONS: Practical weight loss practices such as increased activity, self-selected hypocaloric diet, and group support are effective for weight loss and yield significant health and psychological benefits in moderately obese females.

The case for medical management of obesity: a call for increased physician involvement.

The United States is in the midst of an escalating epidemic of obesity. Over one-third of the adult population in the United States is currently obese and the prevalence of obesity is growing rapidly. By any criteria, obesity represents a chronic disease which is associated with a wide range of comorbidities, including coronary heart disease (CHD), Type 2 diabetes, hypertension and dyslipidemias. The comorbidities of obesity are common, occurring in over 70% of individuals with a BMI of > or = 27. In addition to obesity itself, excessive accumulation of visceral abdominal fat and significant adult weight gain also represent health risks. Physicians have an important role to play in the treatment of obesity. Unfortunately, the medical community has not been involved actively enough to help stem the major epidemic of obesity occurring in the United States. This article puts forth a proposed model for the treatment of obesity in clinical practice, including obtaining the "vital signs" of obesity, recommending lifestyle measures, and instituting pharmacologic therapy when appropriate. By utilizing a chronic disease treatment model, physicians can join other health care professionals to effectively treat the chronic disease of obesity. Relatively modest weight loss, on the order of 5-10% of initial body weight can result in significant health improvements for many patients and represent an achievable goal for most obese patients.

Psyllium-enriched cereals lower blood total cholesterol and LDL cholesterol, but not HDL cholesterol, in hypercholesterolemic adults: results of a meta-analysis.

We conducted a meta-analysis to determine the effect of consumption of psyllium-enriched cereal products on blood total cholesterol (TC), LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels and to estimate the magnitude of the effect among 404 adults with mild to moderate hypercholesterolemia (TC of 5.17-7.8 mmol/L) who consumed a low fat diet. Studies of psyllium cereals were identified by a computerized search of MEDLINE and Current Contents and by contacting United States-based food companies involved in psyllium research. Published and unpublished studies were reviewed by one author and considered eligible for inclusion in the meta-analysis if they were conducted in humans, were randomized, controlled experiments, and included a control group that ate cereal providing /=50 y) on blood lipids. The meta-analysis showed that subjects who consumed a psyllium cereal had lower TC and LDL-C concentrations [differences of 0.31 mmol/L (5%) and 0.35 mmol/L (9%), respectively] than subjects who ate a control cereal; HDL-C concentrations were unaffected in subjects eating psyllium cereal. There was no effect of sex, age or menopausal status on blood lipids. Results indicate that consuming a psyllium-enriched cereal as part of a low fat diet improves the blood lipid profile of hypercholesterolemic adults over that which can be achieved with a low fat diet alone.

The importance of fat free mass maintenance in weight loss programmes.

Obese individuals have excess total body mass, a condition resulting from an overaccumulation of both fat and fat free mass (FFM). Research has been focusing on the need to maintain FFM during weight loss because of its integral role in metabolic rate regulation, preservation of skeletal integrity and maintenance of functional capacity. It has been suggested that FFM loss should compose no more than 30% of total weight loss. Because skeletal muscle in the obese has been shown to consist of an increased amount of low density muscle tissue, impaired strength: size ratio, less capillarisation, decreased mitochondrial density, and consequently impaired work capacity, it may be necessary to stratify FFM into essential and less essential FFM categories. With this categorisation, more specific quantification of FFM loss and maintenance can be made. While FFM influences several physiological functions, it may be that a minimal loss of FFM from the obese state is not only unavoidable, but actually desirable if the loss is in the form of less essential FFM.

Overweight and health: communications challenges and opportunities.

Overweight is associated with multiple adverse health consequences, many of which have been addressed by the experts participating in this Roundtable on Healthy Weight organized by the American Health Foundation. While research and vigorous debate continue on the etiology, treatment, and prevention of obesity, health care professionals face a crucial challenge: effectively communicating current knowledge of the links between overweight and adverse health outcomes. Communications challenges that must be overcome include the clutter of diverse messages, distrust of experts, the anti-diet movement, public confusion, and misunderstandings about scientific reports. An effective communications strategy needs to focus on simple, friendly messages that are consistent with scientific evidence yet understandable to individuals in ways that promote acknowledgment of personal responsibility and promote action.

Fat-free mass is maintained in women following a moderate diet and exercise program.

Weight-loss programs usually result in fat-free mass (FFM) loss along with body-fat (BF) loss. This study examined which combination of diet + exercise would maintain FFM. Forty-four overweight, inactive women completed 20 wk of a randomized intervention: control (C, N = 6), diet only (D, N = 10), diet + cycling (DC, N = 8), diet + resistance training (DR, N = 11), or diet + resistance training + cycling (DRC, N = 9) group. FFM and %BF were determined from hydrostatic weighting. Exercise sessions were attended 3 d.wk-1, with a mean duration of 30 min per session. Caloric intake was reduced 628 kcal.d-1 (+/- 59). Chi squares and ANOVA showed no baseline differences between groups for socioeconomic status, age, body composition, aerobic capacity, or strength. One-way ANOVA of change with Student-Newman Keul multiple range post-hoc tests (P < 0.05) were used to analyze pre to post differences for %BF, body mass (BM), FFM, VO2max, and strength. D, DC, DR, and DRC lost significant BM (-3.7 to -5.4 kg) in comparison with C (+ 1.5 kg). All groups maintained FFM but only DRC significantly lowered %BF (-4.7%) in comparison with C. DRC and DC significantly increased VO2max. Strength 1RM (triceps extension, arm curl, leg extension, chest press) increased significantly for both DR and DRC. Results suggest that moderate levels of caloric restriction, aerobic cycle exercise, and/or resistance training are equally effective in maintaining FFM while encouraging body mass loss.

Chronic psychological effects of exercise and exercise plus cognitive strategies.

Psychological changes associated with 16-wk moderate and low intensity exercise training programs, two of which possessed a cognitive component, were evaluated. Subjects were healthy, sedentary adults, 69 women (mean age = 54.8 +/- 8.3 yr) and 66 men (mean age = 50.6 +/- 8.0 yr). Participants were randomly assigned to a control group (C), moderate intensity walking group (MW), low intensity walking group (LW), low intensity walking plus relaxation response group (LWR), or mindful exercise (ME) group-a Tai Chi type program. Women in the ME group experienced reductions in mood disturbance (tension, P < 0.01; depression, P < 0.05; anger, P < 0.008; confusion, P < 0.02; and total mood disturbance, P < 0.006) and an improvement in general mood (P < 0.04). Women in the MW group noted greater satisfaction with physical attributes (body cathexis, P < 0.03), and men in MW reported increased positive affect (P < 0.006). No other differences were observed between groups on measures of mood, self-esteem, personality, or life satisfaction. Equivocal support is provided for the hypothesis that exercise plus cognitive strategy training programs are more effective than exercise programs lacking a structured cognitive component in promoting psychological benefits.

Nonexercise regression models to estimate peak oxygen consumption.

The purpose of this study was to develop a VO2peak prediction model derived from nonexercise (N-EX) based predictors. VO2peak was measured using a walking treadmill protocol with 229 females and 210 males between 20 and 79 yr of age (mean +/- SD: 38.62 +/- 10.36 ml.kg-1.min-1). Subjects were randomly divided into validation (V) (85% of total; N = 374) and cross-validation (CV) (15% of total; N = 65) groups. The V group was used to validate generalized and gender-specific models using stepwise multiple regression procedures with gender, age and age2, percent body fat, and a physical activity code (AC). The generalized ml.kg-1.min-1 (R2 = 0.77, SEE = 4.90 ml.kg-1.min-1, SEE% = 12.7%) and gender-specific (females: R2 = 0.72, SEE = 4.64 ml.kg-1.min-1; males: R2 = 0.72, SEE = 5.02 ml.kg-1.min-1) models were highly accurate relative to N-EX and exercise based models in the literature. Cross-validation procedures were used to evaluate model stability. The generalized model was stable across the total CV group and various CV subsamples (by gender, decade-wide age groups, and AC groups), but not across groups similar in VO2peak. These results suggest that N-EX models can be valid predictors of VO2peak for heterogenous samples.