THE EFFECTIVENESS OF A COMPUTER AND INTERNET-BASED SYSTEM IN A SHORT-TERM BEHAVIORAL WEIGHT LOSS INTERVENTION

THE EFFECTIVENESS OF A COMPUTER AND INTERNET-BASED SYSTEM IN A SHORT-TERM BEHAVIORAL WEIGHT LOSS INTERVENTIONKristen M. Polzien, PhD.University of Pittsburgh, 2005Computer and Internet-assisted weight loss interventions offer alternative delivery channels that might increase program appeal and potentially increase weight loss success. To date research focused on these innovative techniques is limited. PURPOSE: To examine the effectiveness adding a technology-based intervention component to an in-person, 12-week clinically-based behavioral weight loss intervention. METHODS: Fifty-seven subjects (body mass index = 33.1+/-2.8 kg/m2; age = 41.3+/-8.7 yrs) participated in a 12-week intervention with random assignment to Standard Behavioral Program (SBWP), Intermittent Technology-Based Program (INT-TECH), or Continuous Technology-Based Program (CON-TECH). SBWP received an individual weight loss session at weeks 1-4, 6, 8, and 10, prescribed a diet of 1200-1500 kcal/d, and exercise progressing from 20-40 min/d on 5 days/wk. INT-TECH and CON-TECH received the components of SBWP, however, these groups also used a SenseWear Pro Armband (BodyMedia, Inc.) to monitor energy expenditure and a web-based program to monitor eating behaviors. INT-TECH used these features during weeks 1, 5, and 9, with CON-TECH using these features throughout the 12-week intervention. Outcomes included body weight, percent body fat, and cardiorespiratory fitness. RESULTS: Fifty subjects completed the investigation (88%). Intent-to-treat analysis revealed weight loss of 4.1+/-2.8 kg (4.6 +/-2.8%), 3.4+/-3.4 kg (3.8+/-3.8%), and 6.2+/-4.0 kg (7.1+/-4.6%), for the SBWP, INT-TECH, and CON-TECH groups, respectively (CON-TECH greater than INT-TECH, p less than/equal to 0.05). Percent body fat was significantly decreased in CON-TECH (-4.1+/-2.9%) when compared to both SBWP (-1.6+/-1.5%) and INT-TECH (-1.6+/-1.7%) (p less than/equal to 0.05). Cardiorespiratory fitness significantly increased in all groups by 14%, 3%, and 5% in SBWP, INT-TECH, and CON-TECH, respectively; p less than 0.01), with no significant group differences. CONCLUSIONS: Results indicate that a technology-based program that is used continuous over a 12-week intervention and is complimentary to a clinically-based in-person intervention improves weight loss by approximately 3% compared to a SBWP that does not use these technology features or by approximately 3.7% compare to INT-TECH uses the technology features only intermittently during the intervention. Considering these short-term results, future studies should examine the impact of adding these technology features to a SBWP on long-term weight loss outcomes, and for whom technology-based programs are most effective

The small community solar thermal power experiment. Parabolic dish technology for industrial process heat application

Aspects of incorporating a thermal energy transport system (ETS) into a field of parabolic dish collectors for industrial process heat (IPH) applications were investigated. Specific objectives are to: (1) verify the mathematical optimization of pipe diameters and insulation thicknesses calculated by a computer code; (2) verify the cost model for pipe network costs using conventional pipe network construction; (3) develop a design and the associated production costs for incorporating risers and downcomers on a low cost concentrator (LCC); (4) investigate the cost reduction of using unconventional pipe construction technology. The pipe network design and costs for a particular IPH application, specifically solar thermally enhanced oil recovery (STEOR) are analyzed. The application involves the hybrid operation of a solar powered steam generator in conjunction with a steam generator using fossil fuels to generate STEOR steam for wells. It is concluded that the STEOR application provides a baseline pipe network geometry used for optimization studies of pipe diameter and insulation thickness, and for development of comparative cost data, and operating parameters for the design of riser/downcomer modifications to the low cost concentrator

Wechselbeziehungen zwischen endogenem veränderlichen Testosteronspiegel und fettfreiem Körpergehalt bei Jungen und Älteren Sportlern

The purpose of this study was to examine the endogenous circulating testosterone levels and lean body mass (LBM) in young to middle-aged physically active - sportsmen to determine, whether there any relationships between these parameters in normal circumstances (i.e., no medical problems or pharmacolo- gical manipulations). Healthy, drug-free men (n=127) were recruited for testing (mean±SD, age 25.0±4.8 yr). Morning blood samples were obtained and underwater weighing was performed to determine the body composition (the measures were: LBM, fat weight [FW], body fat percentage [%fat]). Testosterone (T) was analyzed via RIA. Correlation analysis was performed to determine if thee were any significant relationships between the measures. Coefficients between T and LBM (r = 0.266), FW (r = -0.255), and %fat (r = -0.280) were significant (p<0.005). These findings show that endogenous testosterone and LBM are significantly related to one another in physically active men; however, the magnitude of the relationship is moderate at best. This suggests that the LBM component of men (which is comprised primarily of muscle mass) is related to circulating testosterone levels; but it is also strongly influenced by other factors.UVOD Testosteron je anabolički androgeni spolni steroidni hormon povezan sa sintezom proteina. Mnogi veličinu tijela i mišićni razvoj povezuju s razinom testosterona u odraslih muškaraca. Takovo se poimanje razvilo zbog anaboličkih svojstava toga hormona. No, u stvarnosti, stupanj razvoja mišićne mase u pojedinca ovisi i o mnogim drugim faktorima; od kojih su neki fiziološke naravi, neki su vezani za ponašanje pojedinca, dok su drugi nasljedne prirode (Florini, 1987). Ipak, postoje dokazi koji podupiru pretpostavku kako opća razina cirkulirajućeg testosterona može biti, u određenoj mjeri, faktor koji doprinosi količini mišićne mase muškaraca in vivo. Ongphiphadhanakul i suradnici (1999) ustanovili su na uzorku fizički neaktivnih odraslih muškaraca (sedentarni stil života) da je mišićna tjelesna masa značajno povezana s endogenom razinom testosterona. U dvodijelnom modelu konstitucije ljudskog tijela, ono se dijeli na masnu komponentu (udio masnoga tkiva) i na nemasnu tjelesnu masu (LBM – engl. lean body mass). I sama sastavnica nemasne tjelesne mase sastoji se od nekoliko faktora, među kojima je nedvojbeno najvažniji onaj koji se odnosi na masu skeletnih mišića (Behnke, Wilmore, 1974; Brozek i sur. 1963). Neka druga istraživanja pokazala su kako unos testosterona (egzogeni testosteron) povećava nemasnu tjelesnu masu (LBM). Arslanian i suradnici (1997) izvijestili su kako je četveromjesečni tretman testosteronom u adolescenata koji su kasnili u biološkom razvoju (retardanti - zakašnjeli pubertet) rezultiraom povećanjem LBM za 7,6 kg. Bhasin i suradnici (1996) su otkrili da primjena testosterona u odraslih muškaraca povesava LBM, a kada se taj unos kombinira s vježbanjem, tada je povećanje količine nemasne tjelesne mase još veće. Griggs i suradnici (1989) dobili su slične rezultate na temelju jednomjesečne primjene testosterona, kombinirane s trenažnim programom za razvoj snage, što je razultiralo 12%-tnim povećanjem nemasne tjelesne mase te 27%-tnim ubrzanjem i povećanjem sinteze mišićnih proteina. Sveukupno, rezultati navedenih istraživanja potvrduju tvrdnju kako ukupna razina cirkulirajućeg testosterona pozitivno utječe na nemasnu tjelesnu masu (LBM) i, posebice, na mišićnu masu. Taj problem, međutim, nije do sada bio predmetom iscrpnih znanstvenih istraživanja, a osobito se previše pozornosti nije posvećivalo bazalnom statusu uzorka fizički aktivnih muškaraca. Ovo je istraživanje stoga usmjerenjo na ispitivanje razine cirkulirajućeg endogenog testosterona i nemasne tjelesne mase na uzorku zdravih muškaraca kako bi se utvrdilo postoje li relacije među navedenim parametrima i u uvjetima fizički aktivnog svakodnevnog života. ISPITANICI I METODE Uzorak ispitanika činila su 142 zdrava muškarca, koja su dala pismeni pristanak za sudjelovanje u ovom istraživanju. Tjelesne karakteristike uzorka (aritmetička sredina ± standardna devijacija): dob – 25,1±1,4.6 godina (raspon od 18 do 45 godina), tjelesna masa – 77,9±10,8 kg, visina – 176,9±8,8 cm. Ispitanici su odgovorili na jednostavan upitnik o stupnju njihove fizičke aktivnosti. Svaki je ispitanik bio redovito fizički aktivan (3,9±1,3 dana/tjedno; 44±19 min/dan), tj. bio je uključen u neki od mnogobrojnih oblika redovitog tjelesnog vježbanja, od rekreativnog vježbanja do sudjelovanja u natjecateljskim sportskim disciplinama. Mnogi ispitanici bili su sportaši - natjecatelji iz 9 različitih sportova (lacrosse – kanadski nacionalni sport, sličan hokeju na travi, ali se igra specijalnim reketima, op. prev., američki nogomet, atletika – trkači, bacači i skakači, hrvanje, košarka, bejzbol, nogomet, biciklizam i plivanje). Svaki sport bio je zastupljen relativno malim, k tome i nejednakim brojem ispitanika. Zato nisu provedene usporedne analize rezultate ispitanika iz pojedinih sportskih disciplina. Naime, mali uzorci ispitanika iz pojedinačnih sportskih disciplina ugrozili bi statistička načela (Linton i Gallo, 1975). Ispitanici bi se u našemu laboratoriju pojavili približno oko osam sati ujutro, 12 sati nakon posljednjeg obroka. Prvo su se 15 minuta odmarali ležeći na leđima. Nakon toga su im uzeti uzorci krvi iz vene na ruci. Iz krvnih se uzoraka ispitivala opća razina cirkulirajuseg testosterona standardnim radioimunološkim mjernim postupkom (DPC Inc, Los Angeles, CA). Nakon vađenja krvi, ispitanicima je izmjerena tjelesna masa baždarenom medicinskom vagomi (preciznost mjerenja ±0,10 kg). Velikim kliznim antropometrom izmjerena je visina ispitanika (preciznost mjerenja ±0,10 cm). Tijekom mjerenja ispitanici su bili odjeveni samo u kratke sportske hlačice. Provedeno je funkcionalno dijagnosticko testiranje dišnoga sustava kako bi se odredio rezidualni plusni volumen. Podvodno vaganje korišteno je za utvrđivanje građe tijela (Sinning i Hackney, 1984). Na temelju podvodnog vaganja odredena je gustoća tijela koja je uvrštena u formulu Brozeka i suradnika (1963) za izračunavanje postotka tjelesne masnose (% masti). Nemasna tjelesna masa (LBM) i težina masnog tkiva (FW – fat weight) izračunata je na temelju postotnih vrijednosti masnog tkiva. Podaci su obrađeni bivarijatnom linearnom regresijskom korelacijskom analizom. Vrijednosti testosterona su u svim slučajevima predstavljale nezavisnu varijablu, dok su izračunate varijable korištene kao zavisna varijabla (p<0.05). REZULTATI I RASPRAVA Srednja vrijednost koncentracije testosterona u ispitanika iznosila je 26,64 nmol/l (±SD = 12,57), što je vrijednost unutar klinički prihvatljivog raspona za muškarce te dobi (Tietz, 1990). Rezultati dobiveni analizom tjelesne konstitucije bili su LBM = 67,21±9,16 kg, FW =9,18±5,48 kg i postotak masnoga tkiva = 11,75±5,66%). Rezultati regresijske korelacijske analize pokazali su značajnu povezanost između razine testosterona i LBM (slika 1). Neke od ostalih tjelesnih mjera također su pozitivno korelirale s razinom testosterona. Ti su rezultati prikazani u tablici 1. Premda su utvrdene statistički značajne povezanosti između varijabli, dobiven je ralativno nizak stupanj zajedničkog varijabiliteta za udio testosterona u varijanci pojedinih varijabli (< 9.0 %). Primarni zaključak proistekao iz ovog rada ukazuje na značajnu povezanost ukupne količine cirkulirajućeg endogenog testoserona i nemasne tjelesne mase u fizički aktivnih muškaraca. Međutim, veličina povezanosti je, u najboljem slučaju, umjerena. Dobiveni se rezultati uvelike slažu s nalazima Ongphadhanakula i suradnika (1995) koji su isti problem proucavali na uzorku sedentarnih, neaktivnih muškaraca. Hako je navedeno istraživanje obuhvaćalo, na neki način, komparabilnu grupu fizički neaktivnih, sedentarnih muškaraca, smatrali smo kako u našem istraživanju kontrolna grupa nije nužno potrebna. Prema modelu prosječnog muškarca (15 % masnog tkiva, 70 kg tjelesne mase), ukupna masa skeletnih mišića iznosi približno 52 % nemasne tjelesne mase (LBM) (Behnke i Wilmore, 1974). U fizički aktivnih muškaraca taj je postotak u pravilu nešto veći, s mogusnošću da dosegne 60% ili čak i više postotaka (Behnke i Wilmore, 1974). Na temelju takvog odnosa zaključli smo da je sastavnica nemasne tjelesne mase (LBM), a onda i mišisna masa u fizicki aktivnih muškaraca povezana s razinama cirkulirajućeg testosterona. Ipak, i ovdje se također pokazalo da na odnos testosterona i mišićne mase znatno utječu i ostali faktori, poput prehrambenih navika, genetskih, naslijedenih osobina te ostalih endogenih hormona (Florini, 1978). ZAKLJUČAK Mnogi sportaši misle kako postoji snažna izravna veza između razine testosterona i mišićne mase. Zbog toga se neki sportaši poduzimati i krajnje, čak i opasne mjere ne bi li povećali razinu testosterona u svome tijelu (dodaci u prehrani i/ili čak i uzimanje nedopuštenih sredstva, preparata ili dopinga). Autori ovog istraživanja vjeruju kako se dobiveni rezultati poslužiti i pomosi trenerima i kineziolozima da uvjere sportaše u to da je razina testosterona samo jedna od sastavnica u procesu razvoja mišićne mase, kao i da je korištenje doping-sredstava, poput, primjerice, anaboličkih steroida, nepotrebno.Das Ziel dieser Untersuchung war endogenen, veränderlichen Testosteronspiegel und fettfreies Körpergehalt (LBM) bei jungen und ältern Sportler zu messen, um die gegebenfalls vorhandenen Relationen unter den Parametern selbst im durchschnittlichen alltäglichen Umständen (d. h. wenn die Testpersonen einen guten Allgemeinbefund aufweisen ohne jegliche Medikamenteneinnahme) fest zu stellen. An der Untersuchung nahmen freiwillig 142 gesunde Testpersonen teil, die im Alter von 25.1±4.6 keine Medikamente einnahmen. Am Morgen wurden Blutproben genommen und danach wurde unter dem Wasserspiegel das Körpergewicht gemessen, womit der Körperbau (Maßstäbe: fettfreies Körpergehalt(LBM), Fettansatz im Fettgewebe (FW)) und der Fettspiegel (Fett-%) festgesatzt wurden. Testosteronspiegel (IT) wurde über RIA-Methode fest gestellt. Die Angaben wurden über lineare regressive Korrelationsanalyse mit zwei Varianzen bearbeitet, damit fest gestellt wurde, ob es bedeutende Wechselbeziehungen zwischen den Maßstäbe gäbe. Korrelationskoeffizienten zwischen T und LBM (r = 0.299) bzw. FW (r = -0.246) und Fett-% (r = -0.271) waren von einer Bedeutung nur bei P-Wert <0.005). Die Ergebnisse weisen darauf hin, dass der endogene, veränderliche Testosteronspiegel und fettfreise Körpergehalt bei körperlich aktiven Männern eine wechselseitige Beziehung aufweist, obwohl die Beziehung von keiner besonderen Bedeutung ist. Die Ergebnisse zeigen, dass das fettfreie Körpergehalt bei Männern (vowiegend aus Muskelgewebe) mit Schwenkungen imveränderlichen Testosteronspiegel zu tan hätte, dass es aber von anderen Faktoren - Essgewohnheiten, Erbgut und andere endogene Hormone - auch stark beeinflusst wird

Association Between Weight Loss and Physical Activity On Change In Blood Pressure In Overweight Adults

Please view abstract in the attached PDF file

The effect of self-efficacy on behavior and weight in a behavioral weight-loss intervention.

To determine whether eating self-efficacy and physical activity self-efficacy are predictive of dietary intake, physical activity, and weight change within a behavioral weight loss intervention, and whether dietary intake and physical activity mediate relationships between self-efficacy and weight change

The Effect of Physical Activity on 18-Month Weight Change in Overweight Adults

Few studies have been conducted that have examined the long-term effect of different doses of physical activity (PA) on weight change in overweight adults without a prescribed reduction in energy intake. This study examined the effect of different prescribed doses of PA on weight change, body composition, fitness and PA in overweight adults. 278 overweight adults (BMI: 25.0 to 29.9 kg/m2; Age: 18 to 55 years) with no contraindications to PA were randomized to one of three intervention groups for a period of 18 months. MOD-PA was prescribed 150 min/wk and HIGH-PA 300 min/wk of PA. SELF was provided a self-help intervention to increase PA. There was no recommendation to reduce energy intake. MOD-PA and HIGH-PA was delivered in a combination of in-person and telephone contacts across 18 months. 18-month percent weight change was −0.7±4.6% in SELF, −0.9±4.7% in MOD-PA, and −1.2±5.6% in HIGH-PA. Subjects were retrospectively grouped as remaining within ±3% of baseline weight (WT-STABLE), losing >3% of baseline weight (WT-LOSS), or gaining >3% of baseline weight (WT-GAIN) for secondary analyses. 18-month weight change was 0.0±1.3% for WT-STABLE, +5.4±2.6% for WT-GAIN, and −7.4±3.6% for WT-LOSS. 18-month change in PA was 78.2±162.6 min/wk for WT-STABLE, 74.7±274.3 for WT-GAIN, and 161.9±252.6 min/wk for WT-LOSS. The weight change observed in WT-LOSS was a result of higher PA combined with improved scores on the Eating Behavior Inventory, reflecting the adoption of eating behaviors to facilitate weight loss. Strategies to facilitate the maintenance of these behaviors are needed to optimize weight control

Randomized trial comparing group size of periodic in-person sessions in a remotely delivered weight loss intervention

Abstract Background Few randomized studies have examined differential effects of group size in behavioral weight control, especially in hybrid programs that include Internet treatment approaches. Methods Randomized controlled trial (n = 195) comparing a 4 month hybrid internet weight loss program coupled with monthly face to face groups of 100 persons (Large Group, LG; 1 group) or to the same approach with monthly groups of 20 persons (Small Group, SG; 4 groups). Repeated-measures mixed-model analysis with age and race as covariates were used to estimate primary (weight) and secondary outcomes, and to test group differences in change over time. Results The sample was 46.3 years old ±10.4, 90.3% female, and 51.9% non-white, with BMI 37.9 ± 8.4 kg/m2. Participants in the LG were more likely to return for the 4-month assessment visit than those in the SG (p = 0.04). Participants randomized to both the LG and SG conditions experienced significant WL over time (no between group difference: −4.1 kg and −3.7 kg, respectively) and weight loss was positively associated with attendance at monthly meetings and logins to the website. Satisfaction with the program was high and similar in both groups (94.4% reported that they were “satisfied” or “very satisfied”). Conclusions Using a hybrid approach of in-person and online weight loss interventions may be an effective way to reach larger and more diverse populations. Delivering the face to face component of the intervention in groups larger than those traditionally delivered (20–25 people) could increase the cost-effectiveness of group-based behavioral weight loss interventions. Clinical trials registration number NCT01615471 . Registered June 6, 2012. Registered retrospectively

A Review of Accelerometry-Based Wearable Motion Detectors for Physical Activity Monitoring

Characteristics of physical activity are indicative of one’s mobility level, latent chronic diseases and aging process. Accelerometers have been widely accepted as useful and practical sensors for wearable devices to measure and assess physical activity. This paper reviews the development of wearable accelerometry-based motion detectors. The principle of accelerometry measurement, sensor properties and sensor placements are first introduced. Various research using accelerometry-based wearable motion detectors for physical activity monitoring and assessment, including posture and movement classification, estimation of energy expenditure, fall detection and balance control evaluation, are also reviewed. Finally this paper reviews and compares existing commercial products to provide a comprehensive outlook of current development status and possible emerging technologies

eHealth interventions for the prevention and treatment of overweight and obesity in adults: A systematic review with meta-analysis

A systematic review of randomized controlled trials was conducted to evaluate the effectiveness of eHealth interventions for the prevention and treatment of overweight and obesity in adults. Eight databases were searched for studies published in English from 1995 to 17September 2014. Eighty-four studies were included, with 183 intervention arms, of which 76% (n=139) included an eHealth component. Sixty-one studies had the primary aim of weight loss, 10 weight loss maintenance, eight weight gain prevention, and five weight loss and maintenance. eHealth interventions were predominantly delivered using the Internet, but also email, text messages, monitoring devices, mobile applications, computer programs, podcasts and personal digital assistants. Forty percent (n=55) of interventions used more than one type of technology, and 43.2% (n=60) were delivered solely using eHealth technologies. Meta-analyses demonstrated significantly greater weight loss (kg) in eHealth weight loss interventions compared with control (MD -2.70 [-3.33,-2.08], P<0.001) or minimal interventions (MD -1.40 [-1.98,-0.82], P<0.001), and in eHealth weight loss interventions with extra components or technologies (MD 1.46 [0.80, 2.13], P<0.001) compared with standard eHealth programmes. The findings support the use of eHealth interventions as a treatment option for obesity, but there is insufficient evidence for the effectiveness of eHealth interventions for weight loss maintenance or weight gain prevention