Francesca Mancini Prof. Nakamoto October 23, 2012 Final Assignment : Sugar-Sweetened Beverages The article “A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight”(2012) aims at examining the causal relationship between the consumption of sugar-sweetened beverages and obesity among adolescents. The research for this article is a follow up of a previous pilot study that has been conducted on a period of six months involving normal weight, overweight, and obese adolescents who consumed sugar sweetened beverages regularly.
Results showed that there was a significant decrease of body weight and body mass index (BMI) among the overweight and obese adolescents. Due to this result, a further study has been designed to reanalyze the data from the pilot study and further explain the effects of sugar-sweetened beverages. The research method used was a random sample of 224 adolescents that are obese or overweight who consumed at least one serving of sugar-sweetened beverages or fruit juice per day. Participants were randomly assigned to a control group or an experimental group for two years; where one year would be an intervention and the second year a follow up.
Since the participants are young, the parents provided a written consent and the participants a written assent. The multicomponent intervention aimed to reduce the consumption of sugar-sweetened beverages for one year in the experimental group by providing access to home delivery of non-caloric beverages. Motivational telephone calls with parents were conducted on a monthly basis and three check-in visits with participants. The control group on the other hand received $50 supermarket gift cards to participants at four to eight months as a retention strategy but did not instruct them on what to purchase with the cards.
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It is important to note that the study did not focus attention to other diet methods or physical activity, however, they have included the daily physical activity level and the amount of television watched daily. The measures for his study: * Demographics: sex, race, date of birth, ethnic group, parents level of education, and total annual household income. * Physical activity: in collaboration with the persons metabolic equivalence. * Television viewing: hours per day. * Dietary intake: includes three main items. 1) beverages per servings per day: a-sugar-sweetened, b-fruit juices, c-artificially sweetened, d- unsweetened. ) energy intake per calorie per day: a-total, b-sugar-sweetened beverages, c-fruit juices. 3)Sugar grams per day. * Weight and height: in kilograms and centimeters (these are used to compute the BMI * BMI as an outcome over the two years: used the bioelectrical impedance analysis (BIA) to calculate body fat. * Adverse events: any symptom or medical attention that was reported during the study. Hypothesis: One single hypothesis was formulated for this study. They hypothesized that the experimental group would gain weight at a slower rate than the control group.
Results: When testing the covariates for interaction, Hipic ethnic group is found to be the only modifier for group differences, as they have portrayed the most change; causing the study to add an interaction term for the ethnic group. At baseline, regarding the demographics or other variables, there were no differences between the experimental and the control groups. In terms of dietary intake at year one, change in consumption of sugar-sweetened beverages was different between the control and the experimental groups; declining almost to zero for the experimental.
Also meaning that the experimental group consumed more artificially or un-sweetened beverages. At year two, same results remained however, the intake of artificially sweetened beverages did not differ between the groups. Also, sugar intake in both years was less for the experimental group. In terms of the outcomes, at year one the net BMI was significant, but not in year two. When sugar was added to the BMI measure there was no longer a significance. Body fat was not significant among the groups. Although, there was no intervention done for physical activity, the experimental group watched less television.
In terms of ethnic group, among Hipics in the two years, there was significant effect on the BMI, as well as in the change of body weight. The effects of Hipic youth was strong compared to the non-Hipics. Discussion: The results show a support of the hypothesis; the experimental group did gain weight but at a slower rate than the control group. These are shown in the results of the overall BMI computed and the overall weight of the participants. Most of the difference is due to the Hipic participants, as they are the ones that showed to have the most effect out of the intervention.
Even if the overall study did support the hypothesis in quest, there are many discussion points towards the results and the overall study: * The unexpected finding that the Hipics are the ones that have showed the most dominant findings, causing the major change in BMI over two years, is one that should be studied more. It is interesting that they started out with a sample that includes diversity, however, if the Hipics hadn’t been part, the hypothesis wouldn’t have been supported.
There is a reason to why the Hipics have been affected this much, it would be interesting as they have stated, to look more into the physiology and in generic susceptibility. * During the second year, when the intervention was not playing a critical role, there was an effect but not as powerful. The level of consumption of sugar-sweetened beverages and juice had increased a bit and this shows that the intervention was not that efficient as with time this will increase. It is clear that the results of the study were conducted and everything they needed to establish was accomplished, though, the aim is to keep that behavior going.
There should have been a stronger message that could be captured by the participants. * They did not focus on any other diet activity or exercise because their main focus was to check the effect of the sugar-sweetened beverages and non-caloric beverages; wanting to leave everything constant. However, (explaining on a personal level) when people are in an intervention, there is some kind of psychological factor that works to lead to the belief that they are on a certain form of diet; causing them to indirectly adjust other things in heir lifestyle (although in the results shown, people have gained weight overall, but it still makes a small difference). If we look closely at the results in year one, the participants technically did decrease their overall weight because as the height increased, it causes a slight change to the weight, therefore leading to an increase in BMI; whereas in year two, one would think that there would be same constant increase (as the increase in height did not differ much) however, participants gained more than the previous year.
Which leads to the previous point that shows that the intervention was not efficient enough to stay through the follow up, the participants did not continue the behavior change. * The measure of the time spent watching television daily is also a critical factor that was not used much, as it was clearly stated that they were not examining the effect of physical activity or anything else; it was just an overall view. Results stated that the experimental group did spend less hours watching television; maybe it is relevant to the key point stated earlier about the unconscious change in lifestyle. “Missing values for BMI were imputed by assessing that the participants’ BMI z score was unchanged from baseline”(p. 3). Including manipulated data to the results would have an effect on the overall study, the missing information of any participant should just be omitted, as well as the participant itself. * There was no interaction with the parents level of education and the total household income, probably useful to show the differences among social classes; as the study is one of a diverse sample, including differences in all characteristics. * Adverse events were included, however, did not have much significance with the study.. n this study of reduced sugar-sweetened beverages, there are not side effects that could lead to any severe injury. Probably it was necessary to cover everything needed, maybe during a severe injury, the interventions was not followed or the participant have gained or lost weight because of the incident. Impact of paper on intervention: Sugar-sweetened beverages has an effect on the increase of body weight, this was evaluated in the article through an intervention that included the provision of non-caloric beverages to check the difference in weight gain among the two groups of study (experimental and control).
There were some issues that the article “A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight”(2012) does not answer; these are issues that relate to the messages sent out. To start by saying, an intervention in medical terms is “any measure whose purpose is to improve health or alter the course of disease” (Medical Dictionary). In this paper, the intervention aimed at the provision of non-caloric beverages aimed at reducing the consumption of sugar sweetened beverages, however, the message was not strong enough.
It was a trial period of one year to check if sugar sweetened beverages did cause a gain in weight, and whether substituting these with non-caloric beverages would make a difference at a slower pace, and it most certainly did. The researchers did not identify to the participants and their parents what promotes or protects weight gain; they should communicate the effects of these sugar-sweetened beverages, the idea behind using non-caloric beverages, the impact it has on the body, and the aim of modifying the behavior to adjust obesity problems.
The telephone calls every month did not include information, just checking up with parents of child’s consumption. Overall the paper did provide the non-caloric beverages, however, it did not communicate the impact of these beverages body weight. Study proposal: To recap, the study in the article provided emphasized on difference in weight gain over a period of two years. One year was including the intervention where non-caloric beverages were provided, and the other year was a follow up, with no intervention.
The research however, did not focus on any details about the drinks itself or the amount consumed per day, except that it was non-caloric and “diet” beverages. A proposed study that includes different variables of beverage intake is going to be explained shortly. The aim is to review the research and suggest additional variables and measurements that are going to be tested and therefore, predict the results. The research proposed is derived from the study of the article “Reduction in Consumption of Sugar-Sweetened Beverages is associated with weight loss: The Premier Trial” (2009) by Chen, Appel, Loria, et al.
Obesity and overweight rates in Europe are increasing as the years pass and is a serious public health concern, at the range of 7. 6% to 24. 7% as reported by the Statistical Office of European Union (2011). A major factor for this obesity is the increase in dietary energy intake from beverages. Energy intake among European adolescents is on average 1455 ml/day, mostly consumed from sugar-sweetened beverages, fruit juice, and sweetened milk (Duffey et al. , 2011). Calories consumed in liquid for have weak satiety properties and cause poor energy compensation compared with calories from solid food (Chen et al. 2009). Having explained that, it is safe to say that the reduction in liquid calorie intake may lead to weight loss, which leads to the purpose of this study; to examine how changes in the beverages consumption affect weight change among adolescents: * How changes in liquid calorie intake affects the body weight * How changes in consumption of specific beverages affect body weight * The effect of both in terms of time—6 months and 18 months This study is in Europe, more particularly in Switzerland and the sample population is adolescents.
We are going to use the same sample size of 224 adolescents that are overweight or obese and that consume sugar-sweetened beverages, juices, or any form of energy intake in the form of liquids on a daily basis. Just like the previous study, there will be a written informed consent provided by the parents and a written assent provided by the participants. The intervention includes participants to be involved in groups where they receive information and behavioral counseling; information and advice on the impact of sugar-sweetened beverage consumption on body weight.
Each individual receives two 30 min check-in sessions every month as well as group meetings every other week, in addition to the original monthly telephone call with the parents. In this study the control would be the baseline, as everyone is part of the intervention, and all participants would be studied closely in order to see the effects of decreased consumption of sugar-sweetened beverages as time passes. Data collection is done in three parts: at baseline, at 6 months, and at 18 months.
To begin, a questionnaire would be filled in order to get the baseline characteristics of each individual, followed by an interview via telephone to provide the “unannounced” 24 hour dietary intake (including portion size and exercise). This was done every time new results had to be measured, meaning at baseline, 6 months, and 18 months. The hypotheses formulated for the study: Hypothesis 1: changes in consumption of liquid calories will cause a reduction in weight; only when liquid calorie is decreased.
Hypothesis 2: changes in consumption of individual types of beverages will cause a reduction in weight. Hypothesis 3: Weight reduction in terms of any decrease of sugar-sweetened beverages will be greater in 6 months, compared to 18 months. The design presented: Independent variable (what we manipulate): Liquid calories Types of beverages Dependent variable (what we measure): Weight change Design 1 | Body Weight:| Liquid Calories: | 6 months | 18 months | No change | No change | No change| Increase on 100 kcal| Increase | Increase |
Decrease of 100 kcal| Decrease (0. 3kg)| Decrease (0. 2kg)| Design 2 | Body Weight| Beverage Category:| 6 months | 18 months| Decreased by one serving | Sugar-Sweetened| Decrease (0. 5kg)| Decrease (0. 7kg)| Diet Drinks| No effect| No effect | 100% Juice| No effect | No effect| Other (milk, coffee,.. )| Decrease (0. 1kg)| Decrease (0. 2kg)| The measures for this study: * Demographics: sex, race, date of birth, ethnic group, parents level of education, and total annual household income. * Physical activity: in collaboration with the persons metabolic equivalence.
Evaluated in the questionnaire, as a recall of the previous 7 day activity. * Dietary intake: includes portion size 1) beverages per servings per day 2) energy intake per calorie per day: a-sugar-sweetened beverages, b- juices, c- diet drinks. Received through “unannounced” telephone calls 24 hour dietary intake. * Beverages divided into categories: a- sugar-sweetened, b- diet drinks, c- 100% juice, d- other: includes milk, coffee, tea, … * Weight and height: in kilograms and centimeters - these are used to compute the BMI.
Results: The results do show that the change in liquid calorie intake does affect body weight and that a decreased in beverage type will also cause body weight to decrease, however, this is explained in more detail. In terms of hypothesis 1- a decrease in liquid calorie did cause a decrease in body weight. Results have shown that a reduction of 100 kcal was associated with a decrease of 0. 3 kg at 6 months and a 0. 2 kg at 18 months (Chen et al. , 2009).
In terms of hypothesis 2- there was a relationship with beverage type and body loss, however, not with all the beverage types; with some there was no correlation. When tested, a reduction of one serving of sugar-sweetened beverage was significantly associated with weight loss at both 6 months and 18 months. Diet drinks, 100% juice were inversely associated with weight loss, but this was not statistically significant, leading to not effect in weight loss; a decrease of one serving of the other beverages did show a slight decrease in weight loss along both time periods (Chen et al. 2009). In terms of hypothesis 3- weight reduction will be greater at 6 months, compared to 8 months, showed no significance; the opposite occurred. Compared to baseline, as stated in hypothesis 1, the weight loss was greater at 18 months, also proven at a reduction in sugar-sweetened beverages by one serving was associated with a 0. 5kg weight loss at 6 months and a 0. 7kg weight loss at 18 months (Chen et al. , 2009). Meaning at 18 months people lost more weight than at 6 months. Discussion/ Commentaries: From the proposed study, findings have suggested that a reduction in liquid alorie intake was significant with weight loss in both 6 months and 18 months, and that the reduction of sugar-sweetened beverages was also associated with weight loss in these periods of time. The original study by Ebbeling et al. , (2012) was an intervention to reduce the number of sweet-sugar beverages consumed and instead consume the unsweetened beverages or non-caloric beverages. This was studied without advising the participants on the effects of these beverages on the body and overall weight, just by observation and calculation of BMI.
Although the results were aimed at checking the weight gain in two years between a control group and an experimental group, their focus was on the result of the BMI which is a measure relative to weight and height: people had an increased BMI as they were growing taller and gained more mass. In this proposed study however, the intervention is focusing on the opposite outcome, the weight loss with time of using less sugar-sweetened beverages, the measure here was the overall weight difference caused by these beverages, shown in kg. It also includes counseling, advice, and information on the effect of these beverages on the body.
Overall, this is mainly planned so that people could accept this behavior change; and because this is done on obese and overweight participants, the behavior of reducing the intake of these sugar-sweetened beverages is one that should be continued – when participants see a change in the overall weight loss (in which the study has proven to be supported), they would be more motivated to carry on this behavior. It is merely a way of tackling the same issue but in a different way with a stronger intervention - more information given to participants.
Aside research has shown that the link between sugar-sweetened beverages and body weight is related to the high fructose content in these beverages. On the long-term this can promote fat storage and excessive food intake through an increase and change in the hormonal patterns that are related to this issue –called the “postpantrial hormone patterns” (Chen et al. , 2009). This is probably why in hypothesis 2, the other types of beverages did not have an effect on weight change, as they do not have the same amount of fructose.
The different nutritional components of each beverage type has a different effect on the body, some aiding in the process of losing weight and others adding difficulties, while some have no effect. Another point that is interesting to point out is that earlier, the term liquid calories was used, this is to state the specific energy intake, as there are two kinds of energy intake- the liquid and the solid form; this study is focusing on the liquid calorie intake of most prominent beverages. Strengths and Limitations:
Some strengths of this study is the duration of the study, it was long enough to test if there is a significant difference in the change of consumption of sugar-sweetened beverages, also the ability to evaluate a variety of beverages and knowing the effects of each on the body, as this might affect the overall effect. Another strength would be the responsiveness and excellent participation rate on the group meetings, the individual session, and the availability of information about the 24 hour dietary recall to measure dietary intake.
Some might argue that the “unannounced” 24 hour dietary intake may be a little bit faulty, that the dietary intake should be written on a daily or weekly basis in order to evaluate it better; not just done at baseline, 6 months and 18 months. Although this point may seem like a limitation, the study sees it as a strength as the intervention is focusing on the liquid calorie, with the behavioral counseling and advice on increasing or decreasing liquid calories is pretty clear that there is a tight control and a trust that the participants are following what is being told.
Some limitations of this proposed study would be the lack of follow up, the study was aimed at 18 months with the manipulation of calorie intake from different kinds of beverages along with counseling, there was no follow up to see if people maintained the lower calorie intake or not. Another limitation would be the lack of provision of these diet beverages or fruit juices in schools, we have not controlled what and where participants should obtain these beverages, we have just instructed them to do reduce the liquid calorie intake.
The study has used a rather small sample size in order to have more control and focus on all the results yielded; there is no doubt that the results would be different, however, it is always better to pick a larger sample size as we are referring to the country as a whole. What we learned: What we learn from this study is that the reduction in liquid calorie intake is associated with weight loss, specially in the reduction of sugar-sweetened beverages.
In this study, while focusing on the weight in kg, the result change in overall body fat was clear; the overall change in weight because of liquid calorie reduction is not a large amount, however; it does prove that it has an effect on weight gain or weight loss. Moreover, the study supports policy recommendations and public health efforts to reduce intakes of liquid calories, specially the reduction in sugar-sweetened beverages (Chen et al. , 2009).
A number of factors were assumed , however, more prospective studies with accurate measures of exposures and outcomes in terms of body composition are needed to provide more robust evidence on which to base interventions to achieve long-term behavioral change and prevent excess weight gains in adolescents (Rennie, Johnson, & Jebb, 2005). References Chen, L. , Appel, L. J. , Loria, C. , Lin, P. H. , Champagne, C. M. , Elmer, P. J. , … Caballero, B. (2009). Reduction in Consumption of Sugar-Sweetened Beverages is Associated with Weight Loss: the PREMIER Trial. American Society for Nutrition 89:1299-306. Retrieved from http://ajcn. utrition. org/content/89/5/1299. full. pdf+html. Christian Nordqvist. (2011). European Adult Obesity Rates Range From 7. 6% To 24. 7%. Medical News Today. Retrieved from http://www. medicalnewstoday. com/articles/ 238283. php. Ebbeling, C. B. , et al. (2012). A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight. New England Journal of Medicine, 367:15, Oct. 11, 2012, 1407-1416. Intervention. (2007). In Medical Dictionary online. Retrieved from http://medicaldictionary. thefree dictionary. com/intervention. Duffey, K. J. , Huybrechts, I. , Mouratidou, T. , Libuda, L. , Kersing, M. , De Vriendt, … Popkin, B. M. 2011). Beverage Consumption Among European Adolescents in the HELENA Study. Eur J Clin Nutr. 66(2):244-52. doi: 10. 1038/ejcn. 2011. 166. Epub 2011 Sep 28. Retrieved from http://www. ncbi. nlm. nih. gov/pubmed/21952695 Rennie, K. L. , Johnson, L. , Jebb, S. A. (2005). Behavioural Determinants of Obesity. MRC Human Nutrition Research, 19(3):343-58. Just in case: http://ajcn. nutrition. org/content/87/6/1662. short http://pediatrics. aappublications. org/content/123/4/e661. abstract (used as a limitation cy my intervention did not include a policy inclusion in order to deal with the issue) http://ajcn. nutrition. org/content/84/2/274. full
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