Dietary Supplements for Weight Loss.

The Federal Drug Administration has approved, following rigorous testing, 6 pharmacologic agents and one drug in device form for the management of overweight and obesity. Myriad products that purport to act on physiological mechanisms leading to weight loss also pervade the market with minimal regulatory oversight. Systematic reviews and meta-analyses of these products and their ingredients fail to establish any as meaningfully effective at the clinical level. Moreover, safety concerns prevail with adulteration, hypersensitivity reactions, and recognized adverse reactions. Lifestyle, pharmacologic, and bariatric surgical treatments are increasingly available, effective, and safe management tools for practitioners who should council patients, many of whom are susceptible to misinformation, on the lack effective and safe dietary supplements for weight loss.

Gastrointestinal genetic reprogramming of vitamin A metabolic pathways in response of Roux-en-Y gastric bypass.

Roux-en-Y gastric bypass (RYGB) is one of the most performed bariatric surgical techniques. However, RYGB commonly results, as side effects, in nutritional deficiencies. This study aimed to examine changes in the expression of vitamin A pathway encoding genes in the gastrointestinal tract (GI) and to evaluate the potential mechanisms associated with hypovitaminosis A after RYGB. Intestinal biopsies were obtained through double-balloon endoscopy in 20 women with obesity (age 46.9±6.2 years; body mass index [BMI] 46.5±5.3 kg/m2 [mean±SD]) before and three months after RYGB (BMI, 38.2±4.2 kg/m2). Intestinal mucosal gene microarray analyses were performed in samples using a Human GeneChip 1.0 ST array (Affymetrix). Vitamin A intake was assessed from 7-day food records and serum retinol levels were evaluated by electrochemiluminescence immunoassay. Our results showed the following genes with significant downregulation (p≤0.05): LIPF (-0.60), NPC1L1 (-0.71), BCO1 (-0.45), and RBP4 (-0.13) in duodenum; CD36 (-0.33), and ISX (-0.43) in jejunum and BCO1 (-0.29) in ileum. No significant changes in vitamin A intake were found (784±694 retinol equivalents [RE] pre-operative vs. 809±753 RE post-operative [mean±SD]). Although patients were routinely supplemented with 3500 international units IU/day (equivalent to 1050 µg RE/day) of oral retinol palmitate, serum concentrations were lower in the post-operative when compared to pre-operative period (0.35±0.14 µg/L vs. 0.52±0.33 µg/L, respectively - P=0.07), both within the normal range. After RYGB, the simultaneous change in expression of GI genes, may impair carotenoid metabolism in the enterocytes, formation of nascent chylomicrons and transport of retinol, resulting in lower availability of vitamin A.

Scaling of computed tomography body composition to height: relevance of height-normalized indices in patients with colorectal cancer.

BACKGROUND: Body weight scales to height with a power of ≈2 (weight/height2 ), forming the basis of body mass index (BMI). The corresponding scaling of body composition measured by abdominal computed tomography (CT) to height has not been established. The objective of this analysis was to quantify the scaling of body composition measured by a single-slice axial abdominal CT image (skeletal muscle, and visceral, subcutaneous, and total adipose tissue) to height in patients with colorectal cancer (CRC). METHODS: This cross-sectional study included non-Hispanic white males and females, aged 18-80 years, who were diagnosed with stage I-III CRC at an integrated health care system in North America between January 2006 and December 2011. Body composition was measured by a single-slice axial CT image of the third lumbar vertebra and analysed with a semi-automated threshold segmentation procedure. Allometric regression models were used to quantify height scaling powers (ß ± standard error) for each body composition measure, adjusted for age, for males and females. An interaction test was used to determine if height scaling powers were statistically significantly different between males and females. RESULTS: Among 2036 subjects, the mean (standard deviation) age was 64 ± 11 years, 1008 (49.5%) were female, and the mean (standard deviation) BMI was 27.9 ± 5.4 kg/m2 . Powers for skeletal muscle area were 1.06 ± 0.12 for males and 0.80 ± 0.12 for females (P = 0.049). Powers for visceral adipose tissue area were 1.81 ± 0.64 for males and 0.57 ± 0.79 for females (P = 0.16). Powers for subcutaneous adipose tissue area were 2.04 ± 0.42 for males and 0.81 ± 0.45 for females (P = 0.056). Powers for total abdominal adipose tissue area were 1.80 ± 0.46 for males and 0.76 ± 0.50 for females (P = 0.20). CONCLUSIONS: Body composition measured by single-slice axial abdominal CT, particularly muscle area, scales to height with age-adjusted powers that are different than 2 and are distinct between males and females. These observations may have implications for the development of height-adjusted body composition indices in patients with cancer.

Dietary supplements and alternative therapies for obesity: A Perspective from The Obesity Society's Clinical Committee.

In this Perspective Statement from The Obesity Society, the Clinical Committee discusses the use of weight loss supplements in the United States and the lack of regulatory oversight and rigorous testing of their efficacy and safety. A number of products and services claiming to promote weight loss are directly marketed to individuals with obesity and those wanting to lose weight. These products are not regulated as "drugs" by the Federal Drug Administration but, rather, are treated as dietary supplements if ingredients are "generally regarded as safe," requiring little or no testing to show efficacy or safety. Health care providers should be aware of the lack of evidence and deficiencies in regulatory oversight of dietary supplements marketed for weight loss. Regulatory authorities should protect consumers by ensuring accurate and safe marketing claims and preventing promotion of unproven and potentially unsafe products and claims.

A Systematic Review of Dietary Supplements and Alternative Therapies for Weight Loss.

OBJECTIVE: Dietary supplements and alternative therapies are commercialized as a panacea for obesity/weight gain as a result of the minimal regulatory requirements in demonstrating efficacy. These products may indirectly undermine the value of guideline-driven obesity treatments. Included in this study is a systematic review of the literature of purported dietary supplements and alternative therapies for weight loss. METHODS: A systematic review was conducted to evaluate the efficacy of dietary supplements and alternative therapies for weight loss in participants aged ≥18 years. Searches of Medline (PubMed), Cochrane Library, Web of Science, CINAHL, and Embase (Ovid) were conducted. Risk of bias and results were summarized qualitatively. RESULTS: Of the 20,504 citations retrieved in the database search, 1,743 full-text articles were reviewed, 315 of which were randomized controlled trials evaluating the efficacy of 14 purported dietary supplements, therapies, or a combination thereof. Risk of bias and sufficiency of data varied widely. Few studies (n = 52 [16.5%]) were classified as low risk and sufficient to support efficacy. Of these, only 16 (31%) noted significant pre/post intergroup differences in weight (range: 0.3-4.93 kg). CONCLUSIONS: Dietary supplements and alternative therapies for weight loss have a limited high-quality evidence base of efficacy. Practitioners and patients should be aware of the scientific evidence of claims before recommending use.

Usefulness of raw bioelectrical impedance parameters in tracking fluid shifts in judo athletes.

Bioelectrical impedance (BI) has been widely used but clarification about the behaviour of raw BI measurements under specific athletic conditions is required. Thus, we determined the usefulness of raw BI measures in tracking body fluids changes during the preparation period prior to competition in elite Judo athletes. At baseline (weight stability), 27 male athletes were evaluated (23.2 ± 2.8y) and again 1-3 days before competition (∼1-2 months apart). Athletes were free to gain/lost weight based upon specific competition needs. Using dilution techniques (deuterium and bromide), total-body water (TBW) and extracellular water were estimated, and intracellular water calculated as TBW minus extracellular water. Body fluid distribution was determined as Extra-to-/Intracellular water (E/I). Fat and fat-free mass (FFM) was assessed by dual-energy x-ray absorptiometry. Resistance, reactance, and phase angle (PhA) were obtained from bioelectrical impedance spectroscopy (50-kHz frequency). No differences in raw BI measures were observed between athletes that lost (N = 17) or gain weight (N = 10), except for fat, FFM, extracellular water, and EI (p < 0.05). After adjusting for FFM and height, resistance explained TBW (ß = -0.047, p = 0.002) and extracelular water (ß = -0.025, p = 0.001). Reactance explained ECW (ß = -0.098, p = 0.004) and EI (ß = -0.004, p = 0.006), while PhA predicted TBW (ß = 1.609, p = 0.047), ICW (ß = 1.899, p = 0.001) and EI (ß = -0.056, p = 0.001). Regardless of body composition changes, athletes who increase reactance and resistance reduced extracellular water and body fluids while those who raised PhA increased intracellular water. Judo athletes who reduced weight, decreased FFM but cellular health was not compromised, as PhA remained stable and, consequently, cell hydration.

Relationship between changes in total-body water and fluid distribution with maximal forearm strength in elite judo athletes.

Among judo athletes, strong grip strength is crucial for performing offensive and defensive maneuvers that rely predominantly on forearm maximal strength (FMS). The study aims were to evaluate changes in total-body water (TBW) and its compartments (extracellular water [ECW] and intracellular water [ICW]) and their relationship with loss of FMS in elite judo athletes. At baseline (weight stability), 27 male elite athletes were evaluated (age: 23.2 ± 2.8 years) and again evaluated 1-3 days before competition. Athletes were free to gain or lose weight based upon their specific competition needs. Using dilution techniques (deuterium and bromide), TBW and ECW were estimated, and ICW was calculated (ICW = TBW - ECW). Fat, fat-free mass, and appendicular lean soft tissue (LST) were assessed by dual-energy x-ray absorptiometry. Handgrip was used to assess FMS. Using a reduction of 2% as a representative outcome for decreased FMS, 10 athletes were identified as having lost FMS, whereas 17 changed <2% or gained. Comparison of means and logistic regression analysis were performed. Results from baseline to before competition indicated that those who lost ≥2% of FMS significantly decreased TBW and ICW by -2.7 ± 3.0 and -4.4 ± 4.2%, respectively. The groups differed in ICW changes (-4.4 ± 4.2 vs. 1.9 ± 6.1%), respectively, for those who lost FMS by ≥2%. The ICW changes, but not in TBW or ECW, significantly predicted the risk of losing FMS (ß = 0.206; p = 0.027), even adjusting for weight and arm LST changes. These findings indicated that reductions in ICW increased the risk of losing grip strength in elite judo athletes.

Lifestyle interventions for the treatment of class III obesity: a primary target for nutrition medicine in the obesity epidemic.

Although rates of obesity have increased universally in the United States over the past 30 y, it is clear that certain individuals are more susceptible to weight gain than others. Extreme obesity [body mass index (in kg/m(2)) > 40] is increasing at rates greater than any other class of obesity in the United States. Severely obese patients often suffer from a wide variety of comorbidities. Although weight-loss surgery is the most effective treatment, it offers little in the way of large-scale containment due to its costly and invasive nature. Lifestyle interventions that induce modest weight loss and improve fitness can significantly lower disease risk. As medical professionals in the field of nutrition, we must focus first on the patient cohort that suffers most from the modern obesogenic environment. Lifestyle interventions specifically targeted toward the class III obese cohort should be a high priority in nutrition medicine.

In vivo MRI evaluation of anabolic steroid precursor growth effects in a guinea pig model.

Anabolic steroids are widely used to increase skeletal muscle (SM) mass and improve physical performance. Some dietary supplements also include potent steroid precursors or active steroid analogs such as nandrolone. Our previous study reported the anabolic steroid effects on SM in a castrated guinea pig model with SM measured using a highly quantitative magnetic resonance imaging (MRI) protocol. The aim of the current study was to apply this animal model and in vivo MRI protocol to evaluate the growth effects of four widely used over-the-counter testosterone and nandrolone precursors: 4-androstene-3 17-dione (androstenedione), 4-androstene-3beta 17beta-diol (4-androsdiol), 19-nor-4-androstene-3beta-17beta-diol (bolandiol) and 19-nor-4-androstene-3 17-dione (19-norandrostenedione). The results showed that providing precursor to castrated male guinea pigs led to plasma steroid levels sufficient to maintain normal SM growth. The anabolic growth effects of these specific precursors on individual and total muscle volumes, sexual organs, and total adipose tissue over a 10-week treatment period, in comparison with those in the respective positive control testosterone and nandrolone groups, were documented quantitatively by MRI.

Greater resting energy expenditure and lower respiratory quotient after 1 week of supplementation with milk relative to supplementation with a sugar-only beverage in children.

Previous studies have linked overweight to lower milk and calcium consumption and have proposed a role of milk consumption on energy expenditure (EE). The goal of this study was to compare EE and food intake after a meal of either mixed-nutrient or single-nutrient beverage and examine whether supplementation with that beverage for 1 week will impact EE. This was a randomized, controlled crossover study testing the effect of 2 beverages, milk or fruit-flavored beverage, before and after a supplementation period of 1 week on EE. Food intake at a meal after a snack intake of each beverage was assessed at the end of each measurement period. Ten children, aged 9 to 10 years, participated in all of the testing sessions in the study. There was a significant beverage by testing day interaction on daily EE and thermic effect of food (TEF), whereby EE was greater with milk consumption relative to the fruit-flavored beverage on day 8 (P = .0014) and with fruit-flavored beverage consumption on day 1 vs day 8 (P = .01). Similarly, the TEF was greater with milk compared with fruit-flavored beverage consumption on day 8 (P = .0007) and with fruit-flavored beverage consumption on day 1 relative to day 8 (P = .0097). The TEF declined more rapidly during 6 hours after a fruit-flavored beverage than a milk meal (P = .0018). Food intake did not differ after snack consumption of each beverage before and after milk and fruit-flavored beverage supplementation periods. Over the longer term, consumption of milk beverages may have more favorable effects on energy balance in children than consumption of fruit-flavored beverages.

Effect of calcium supplementation on weight and fat loss in women.

Data suggest that a diet deficient in calcium is associated with higher body weight and that augmenting calcium intake may reduce weight and fat gain or enhance loss. Our aim was to determine whether calcium supplementation during a weight loss intervention affects body fat or weight loss. Data were combined from three separate 25-wk randomized, double blind, placebo-controlled trials of 1000 mg/d calcium supplementation in 100 premenopausal and postmenopausal women. The primary outcome measures were change in body weight and fat mass adjusted for baseline values. There were no significant differences in body weight or fat mass change between the placebo and the calcium-supplemented groups in the pooled analysis (adjusted mean +/- SE; body weight, placebo -6.2 +/- 0.7 vs. Ca -7.0 +/- 0.7 kg; fat mass, placebo -4.5 +/- 0.6 vs. Ca -5.5 +/- 0.6 kg), and no significant interactions of calcium supplementation with menopausal/diet status. Analysis as separate trials also found no significant differences between the placebo and the calcium groups. Calcium supplementation did not significantly affect amount of weight or fat lost by women counseled to follow a moderately restricted diet for 25 wk. Nevertheless, the magnitude and direction of the differences for group means are consistent with a hypothesized small effect.

Usefulness of artificial sweeteners for body weight control.

Artificial sweeteners provide lower calorie food products but have been thought to increase appetite and perhaps lead to increased body weight compared with high-sucrose foods. A recent trial demonstrated that subjects supplementing their diets with artificially sweetened foods lost weight, whereas those consuming high-sucrose foods gained weight. This review sheds some light on the controversy regarding the effects of artificial sweeteners in body weight control.