Impact of high fat high calorie diet on depression anxiety and energy levels

¶ … High-Fat, High Calorie Diet on Depression, Anxiety and Energy Levels

The methodology of a study is particularly important, because those who read the study must be able to understand what the researcher did, and those who want to replicate the study need to be able to do so without becoming confused about the researcher's goals, ideas, and beliefs. Discussed here will be information about the sample, the variables, the analysis, and the procedures used, so as to clarify any concerns that might otherwise be seen.

Subjects will be recruited through public advertising for volunteers to participate in an 8-week study regarding diet, panic, anxiety, and energy levels. They will be screened to include only non-depressed women between the ages of 18 and 28 years of age with a BMI between 18.5 and 24.9. No more than 25 subjects will be recruited due to time, space, and budget constraints. Recruiting only non-depressed women between 18 and 28 years of age will be done for two reasons - to start the study with a baseline of healthy subjects in a specific weight range, and because depression and anxiety are both much more common (or at least much more highly reported) in women than they are in men (Hudson, 2000). None of the subjects will have current, diagnosed psychological illnesses, such as bipolar disorder, obsessive-compulsive disorder, schizophrenia or another psychological problem.

All subjects will be asked to complete a Health Status Questionnaire asking about their basic health history, any past anxiety experiences or depressive episodes, and various family illnesses. This is done in order to control for problems that may already be in someone's past or that may run in their family, and to determine whether anxiety or depression was or may be a background problem or family problem for any of the volunteers. In addition, the individuals who participate in this study will be informed in writing that this study is done with their consent as volunteers, and that they do not have to answer any question or perform any test that makes them uncomfortable. They will be able to leave the study at any time without any penalty if they determine that they are not comfortable with the requirements of the study.

Procedure and design

The subjects' diets will be monitored with their consent upon their beginning participation in the study. The subjects will then be fed all of their meals at the clinic, and each one of these meals will be designed so that each subject each day meets the 35% fat and 3500 calorie range. For volunteers to be good candidates for participation in the study, they need to live close to the clinic and/or be willing to come there every day, three times a day, for eight consecutive weeks, in order to ensure that they are getting a specific amount of fat and calories. Every Wednesday, the volunteers in the study will come in after they have eaten their dinner, and they will then be asked to perform various tests and self-assessments. The blood of each volunteer will be drawn during this time in order to measure their serotonin levels. The level of serotonin in a person's blood is believed to be a direct indicator of whether that person is depressed. The higher the level of serotonin, the lower the level of depression that an individual allegedly feels.

There will also be a 10 to 15 minute Center for Epidemiological Studies Depression Scale (CES-D) given and tracked, and the volunteers will answer the questions on the Beck Depression Inventory. In the Beck Depression Inventory patients are diagnosed as having a major depression if they have at least one core symptom such as depressed mood or loss of interest and at least four other symptoms (Lewis & Cachelin, 2001). If a subject is diagnosed with minor depression, this means that they have at least one core symptoms and two additional symptoms, but a total symptom quantity of less than five. This statistical tool has been around for some time, and is particularly significant in determining both the rate of depression and the severity of it (Hewitt, et al., 2001).

The STAI (a test for anxiety) will also be recorded at that time. Both transient (such as panic attacks) and enduring (such as chronic anxiety disorders) levels of anxiety are measured with the STAI. In the STAI, the researcher asks the subjects how they feel at the moment and in the recent past, and how they anticipate feeling in the future (Benazon & Coyne, 2000). This test is designed to overlap between depression and anxiety scales by measuring the most common anxiety symptoms which are minimally shared with depression (American, 1994). Both physiological and cognitive components of anxiety are addressed in the 21 items describing subjective, somatic, or panic-related symptoms (Kingsbury & Williams, 2003).

Once those tests are completed, the volunteers will be asked to cycle on an ergometer for 30 minutes. The Talk Test, Target Heart Rate Evaluation, and the Borg Rating of Perceived Exertion Scale will all be administered while the volunteer is cycling. This is done to determine the energy level - or the perceived energy level - of the volunteer. All of these tests and this same specific pattern will be repeated throughout the entire study, which is eight weeks in length.

Independent Variable

The independent variable in this study will be the diet measurement. While the volunteers get all three meals at the clinic, there is some concern that this does not constitute their entire diet. There is no way, for example, to control what they eat while they are not at the clinic. They may eat a lot of high-fat snacks, or they may eat fruits and vegetables. They may eat nothing other than the meals that the clinic provides for them. This is one area, however, that the researcher is unable to control. Asking these individuals to record any snacks or liquids that they might consume and their fat and calorie content for eight weeks is not feasible, and would likely be inaccurate in many cases. Compensation should be offered for something that would be this intrusive to a person's life, and there is no compensation available for this study. The researcher must simply take into account that the snacking habits of the volunteers have the potential to affect the outcome of the study.