Discuss the findings of your results section and what they mean for future practice (and conclusions about your project).
**Please make sure to upload your entire document template and not just your Chapters 5 and 6 this week. Thank you!
This assignment is worth 50 points, graded as follows:
Meets
Nearly Meets
Does Not Meet
CHAPTER 4
DISCUSSION
The purpose of this review was to research the scientific evidence currently available on a
whole food diet in guiding prevention and reduction of cardiovascular disease. It was
hypothesized that adhering to a Med diet or DASH diet would have cardio-protective effects in
reducing the outcomes of CVD death, fatal or nonfatal MI, stroke, and/or heart failure. The aim
of the present study was to assess the association between adhering to a Med diet or DASH diet
on incidence of CVD and CVD mortality.
The majority of studies on a Med diet included in this review supported the hypothesis that
there was an inverse relationship to CVD mortality, and CV events including MI, heart failure,
and stroke for primary prevention. A systematic review of intervention studies on a Med diet for
both primary and secondary prevention of CVD had limitations of not reporting on outcomes of
CVD end points, along with low quality evidence for CVD mortality.11 The findings of the
review at hand further quantify the protective effect of a Med diet on the risk of CVD for
primary prevention including CHD, MI, and IS, but not for ICH.
The majority of studies on a Med diet included in this review supported the hypothesis
that there was an inverse relationship to CVD mortality, and CV events including MI, HF, and
stroke for primary prevention. A systematic review of intervention studies on a Med diet for both
primary and secondary prevention of CVD had limitations of not reporting on outcomes of CVD
end points, along with low quality evidence for CVD mortality.11 The findings of the current
review further quantify the protective effect of a Med diet on the risk of CVD for primary
prevention including CHD, MI, and IS, but not for ICH.
13
Olive oil, foods containing polyphenols, and fish are components of a Med diet that were
studied independently. The PREDIMED study was a landmark intervention study that supported
the protective effects of olive oil on heart disease in primary prevention.59 This study compared
three diets: a Med diet supplemented with extra-virgin olive oil, a Med diet supplemented with
mixed nuts, or a control diet. They found a reduced risk of CV events, including MI, stroke, or
death after 4.8 years of follow-up in the two diet groups consuming olive oil and nuts. Extravirgin olive oil contains a high amount of oleic acid, a monounsaturated fatty acid, as well as
phenolic compounds, particularly hydroxytyrosol, that have anti-inflammatory properties. The
studies in this review are in consensus with the literature findings of reduced CVD mortality with
inclusion of olive oil within a Med diet. Still, future research may determine whether the
cardioprotective effects of olive oil may be observed only in people at normal or overweight
status, but not in obese individuals.
A Med diet is known for its inclusion of olive oil, as well as other foods that contain rich
sources of polyphenol compounds, including fruits and vegetables, wine, coffee, tea, cocoa,
whole grains, and nuts. The two studies on polyphenol intake included in this review found a
reduced incidence of CV events, particularly for anthocyanins (found in cherries, strawberries,
red wine, fruits), catechins (found in tea, chocolate, apples, red wine), and flavonols (found in
tea, fruits, vegetables, onions, spinach, red wine). The results of these studies on individual food
components support inclusion of olive oil and polyphenols in reducing incidence of CVD;
regardless, the results of the studies that attempted to discover an improvement in CHD, stroke,
or CV mortality by the increase in n-6 polyunsaturated fatty acids from increased fish intake
were inconclusive.
14
The studies on secondary prevention were limited. This review included six studies regarding
a Med diet, DASH diet, and inclusion of olive oil for secondary prevention of CVD, in which no
consensus could be drawn. Future scientific research is needed for secondary prevention in
detecting a whole food dietary pattern for CVD reduction, including the CVD subtypes of MI,
heart failure, and ischemic stroke.
The findings of studies on a Med diet and a DASH diet support clinical practice
recommendations for primary prevention of CVD. The next beneficial steps would involve the
inclusion of the recommendations for following a DASH diet, in addition to the already included
Healthy Mediterranean-Style Eating Pattern, within the forthcoming 2020-2025 Dietary
Guidelines. Additionally, updating the CVD Primary Prevention Guidelines to include
educational resources available for implementation of a whole-food diet based on the MDS and
DASH diet scores is needed.61 For instance, illustrations of sample menus based on a Med diet
and DASH diet are educational tools that could be utilized to facilitate teaching adults heart
healthy eating habits.
There were several strengths to this review. It compared literature between a Med diet, a
DASH diet, as well as a Med diet compared with a DASH diet. Furthermore, studies that
represented thirteen countries increased generalizability of the evidence. Nevertheless, there
were limitations to this review. Dietary instruments, particularly the food frequency
questionnaires, have not been validated for multiple populations’ food preferences based on
culture, ethnicity, and economic status.19 On the other hand, the majority of studies used one
dietary assessment scoring tool, either introduced by Trichopoulou et al.62 or introduced by Fung
et al.61 making comparisons between the studies more uniform. Overall, the main limitation of
this review was a lack of literature on the effects of a Med diet and a DASH diet on secondary
15
prevention of CVD. Also, more studies are needed to dive deeper into the effects of these whole
food diets on heart failure.
16
CHAPTER 5
CONCLUSION
This review presented the scientific evidence currently available on two diets in guiding
prevention and reduction of cardiovascular disease. The purpose of this review was aligned with
the Million Hearts® initiative of preventing one million strokes and heart attacks by the year
2022. 2 A Med diet or DASH diet contributed positively to primary prevention of CVD, mainly in
reducing incidence of MI, heart failure, and ischemic stroke; but not for hemorrhagic stroke. At
this time, there is no determination on whether adherence to a Med diet or DASH diet was
favored in reducing CVD. As certain populations are at higher risk of CVD, including
individuals who have already suffered from a heart attack or stroke, more research is needed on
the best whole food diet for secondary prevention in reducing the burden of CVD. 2
17
1
Intermittent Fasting for Improving Metabolic Biomarkers: A Systematic Review
2
Results
The search was conducted with three databases: Google Scholar, PubMed, and CINAHL.
The search was conducted with terms such as intermittent fasting, metabolic biomarkers,
overweight, obese, obesity, fasting, BMI, and blood glucose. For current research on the topic,
studies were limited to those published from 2015 to 2023. The studies were also limited to those
with interventional research methodology only. This excludes cross-sectional studies and
systematic reviews. Studies were also selected based on availability of full-text articles,
publication in English language, and the researcher’s evaluation of quality using the JBI critical
appraisal checklists. As shown in the PRISMA diagram, a total of 28 articles were selected from
the database and 2 from an open Internet search for a total of 30 articles included for screening.
The PRISMA diagram shows that after screening, 15 records were excluded. After assessment
and critical appraisal, an additional 6 records were excluded, remaining with only 9 records that
met the inclusion criteria and were assessed as meeting the quality requirements for this study.
The studies prioritized in this review were the randomized controlled trials (RCTs).
Seven of the nine articles included in this review were RCTs. Domaszewski et al. (2020)
recruited women over 60 years and randomized them to an intervention group of 16 hour
complete abstinence from food and the control group followed eating plans reflecting their
previous eating habits. Zouhal et al. (2020) randomized males with obesity during the Ramadan
fasting period to intervention (15-16 hours of fasting) and control group (no fasting).
Additionally, Jamshed et al. (2022) recruited people with obesity in a weight loss clinic and
randomized them to 16 hours fasting (intervention) and a self-selected non-fasting diet.
Kunduraci and Ozbek (2020) randomized researchers to intermittent fasting (16:8) and
continuous energy restriction. Carter et al. (2018) specifically targeted people with type 2
3
diabetes and randomized the participants to intermittent fasting and continuous energy
restriction. Hottenrott et al. (2020) randomized overweight individuals to intermittent fasting and
non-intermittent fasting. In each group, participants were further randomized to taking alkaline
supplement and placebo for a total of four participant groups (Hottenrott et al., 2020). Ravussin
et al. (2019) conducted a randomized cross-over trial with intervention group being an 18-hour
daily fasting period.
Results from the RCTs favor the use of intermittent fasting to lose weight as well as
improve other metabolic biomarkers. Domaszewski et al. (2020) reported an approximate
average of 2 kg weight loss for the experimental group in six weeks for women aged 60 years
and above. Similarly, compared to a self-selected non-fasting meal, obese adults following the
16:8 intermittent fasting plan lost 6.3 kg on average over 14 weeks while the control group lost
an average 4 kg (Jamshed et al., 2022). Additionally, Hottenrott et al. (2020) concluded that
combining intermittent fasting with alkaline supplement results in more weight loss than
intermittent fasting alone.
In addition to weight loss, metabolic biomarkers were also improved. Zouhal et al. (2020)
realized a decline in interleukin-6 and tumor necrosis factor-alpha, two important inflammatory
biomarkers. When compared to continuous energy restriction, intermittent fasting produced
similar results and was not inferior to continuous energy restriction interventions (Kunduraci &
Ozbek, 2020; Carter et al., 2018). Ravussin et al. (2019) recorded reduced desire to eat, increased
metabolic flexibility, and increased fullness in the intermittent fasting group.
The other two studies included in this review were a single-group pre- and post-test
study, and an analysis of two previous controlled trials. Hoddy et al. (2016) assessed changes in
weight, fat mass, and resting metabolic rates before and after an eight-week alternate-day fasting
4
intervention. They reported an average decrease of 3.9 kg in weight, 2.2 kg in fat mass, and
resting metabolic rate of 104 kcal/day (Hoddy et al., 2016). Harvey et al. (2018) examined the
outcomes of two previous RCTs involving obese women and reported an average 7.4% weight
loss.
The risk of bias in these studies is moderate. In the RCTs, blinding was not possible since
participants had to be aware of the diet they are following for adherence. This is a potential risk
of bias due to the possible changes in lifestyle accompanied by the dietary interventions. The
study with a high risk of bias is Zouhal et al. (2020) because there was no true randomization;
participants were assigned to groups based on whether they were willing to participate in
Ramadhan fasting or not. In the non-RCT, Hoddy et al. (2016) used a cross-over trial method
which reduces the risk of bias. These studies present a quality of research and credible findings.
5
References
Carter, S., Clifton, P. M., & Keogh, J. B. (2018). Effect of intermittent compared with
continuous energy restricted diet on glycemic control in patients with type 2 diabetes: A
randomized noninferiority trial. JAMA Network Open, 1(3), e180756-e180756.
https://doi.org/10.1001/jamanetworkopen.2018.0756
Domaszewski, P., Konieczny, M., Pakosz, P., Bączkowicz, D., & Sadowska-Krępa, E. (2020).
Effect of a six-week intermittent fasting intervention program on the composition of the
human body in women over 60 years of age. International Journal of Environmental
Research and Public Health, 17(11), 4138. https://doi.org/10.3390/ijerph17114138
Harvey, J., Howell, A., Morris, J., & Harvie, M. (2018). Intermittent energy restriction for
weight loss: Spontaneous reduction of energy intake on unrestricted days. Food Science
& Nutrition, 6(3), 674-680. https://doi.org/10.1002/fsn3.586
Hoddy, K. K., Gibbons, C., Kroeger, C. M., Trepanowski, J. F., Barnosky, A., Bhutani, S., &
Varady, K. A. (2016). Changes in hunger and fullness in relation to gut peptides before
and after 8 weeks of alternate day fasting. Clinical Nutrition, 35(6), 1380-1385.
https://doi.org/10.1016/j.clnu.2016.03.011
Hottenrott, K., Werner, T., Hottenrott, L., Meyer, T. P., & Vormann, J. (2020). Exercise training,
intermittent fasting and alkaline supplementation as an effective strategy for body weight
loss: A 12-week placebo-controlled double-blind intervention with overweight subjects.
Life, 10(5), 74. https://doi.org/10.3390/life10050074.
Jamshed, H., Steger, F. L., Bryan, D. R., Richman, J. S., Warriner, A. H., Hanick, C. J., &
Peterson, C. M. (2022). Effectiveness of early time-restricted eating for weight loss, fat
6
loss, and cardiometabolic health in adults with obesity: A randomized clinical trial. JAMA
Internal Medicine, 182(9), 953-962. https://doi.org/10.1001/jamainternmed.2022.3050
Kunduraci, Y. E., & Ozbek, H. (2020). Does the energy restriction intermittent fasting diet
alleviate metabolic syndrome biomarkers? A randomized controlled trial. Nutrients,
12(10), 3213. https://doi.org/10.3390/nu12103213
Ravussin, E., Beyl, R.A., Poggiogalle, E., Hsia, D.S., & Peterson, C.M. (2019). Early timerestricted feeding reduces appetite and increases fat oxidation but does not affect energy
expenditure in humans. Obesity 27, 1244–1254. https://doi.org/10.1002/oby.22518
Zouhal, H., Bagheri, R., Ashtary-Larky, D., Wong, A., Triki, R., Hackney, A. C., &
Abderrahman, A. B. (2020). Effects of Ramadan intermittent fasting on inflammatory
and biochemical biomarkers in males with obesity. Physiology & Behavior, 225, 113090.
https://doi.org/10.1016/j.physbeh.2020.113090
Intermittent Fasting for Improving Metabolic Biomarkers: A Systematic Review
By:
Rawan Taha
ARIZONA STATE UNIVERSITY
JUNE 2023
CHAPTER I
INTRODUCTION
Metabolic syndrome in general and obesity specifically are increasingly common health
challenges in the general population. Metabolic syndrome includes conditions such as obesity,
hypertension, type 2 diabetes, and dyslipidemia and these are risk factors for cardiovascular
disease, the leading cause of death globally (Aleksandrova et al., 2018). The rates of conditions
identified under the metabolic syndrome are generally high in the population and this presents a
major challenge to public health. People with metabolic syndrome and those at risk can be
identified using metabolic biomarkers, inflammation indicators detected even in people who
have not developed the health condition yet (Aleksandrova et al., 2018). Addressing metabolic
biomarkers in preventative efforts can help reduce the rates of the syndrome and associated
health complications.
The research problem identified is the high rates of obesity and other metabolic conditions in
the United States. As of 2020, 42.4% of Americans were obese (Hales et al., 2020). Additionally,
49.64% had hypertension with many more undiagnosed cases (Chobufo et al., 2020). Type 2
diabetes mellitus rates are on the rise and so are rates of dyslipidemia. These conditions
contributing to the leading cause of death are increasingly common in the United States public
and an urgent solution is needed to address the public health problem. Dietary changes are
universal approaches to reducing metabolic biomarkers and this research revolves around the
question of intermittent fasting.
Reduction of metabolic biomarkers in people at risk of developing metabolic syndrome has
been studied by numerous researchers and several have focused specifically on intermittent
fasting. Kunduraci and Ozbek (2019) evaluated the effect of intermittent fasting among adults in
Turkey. They compared the 16:8 (16 hours of fasting and eight hour window for eating) with
continuous energy restriction programs and found that both approaches were effective in
reducing metabolic biomarkers (Kunduraci & Ozbek, 2019). Similarly, Rynders et al. (2019)
found that people who took intermittent fasting experienced a similar weight loss result as those
who undertook continuous energy restrictions. The main difference was that Rynders et al.
(2019) conducted systematic review of the literature. From these research articles, intermittent
fasting presents the same efficacy as continuous energy restriction diets. The studies also
establish the safety of intermittent fasting.
Elsewhere, Cho et al. (2019) found that people who used intermittent fasting achieved a
higher level of weight loss than those who used regular diets or continuous diet restrictions.
Their research was also a systematic review hence collating many research findings from
different studies. Findings from the study by Zouhal et al. (2020) also support these findings. The
researchers found that compared to people who did not practice intermittent fasting during
Ramadhan, those who engaged in intermittent fasting experienced a higher rate of weight loss
and a decrease in interleukin and tumor-necrosis factor (Zouhal et al., 2020). These findings
further extend the current research to outline the potential inflammatory pathways for metabolic
biomarkers associated with not only obesity but also cancer. The findings that intermittent
fasting can reduce metabolic biomarkers and contribute to weight loss have also been
corroborated in a Polish study involving older women 65 years and older (Domaszewski et al.,
2020). The researchers compared the intermittent fasting 16:8 method with the maintenance of
previous feeding habits and concluded that the former was superior in weight loss and reduction
of body fat percentage (Domaszewski et al., 2020). From these studies, it is seen that intermittent
fasting may be superior to usual diets and continuous energy restriction in weight loss and
management of some metabolic biomarkers.
Other studies have focused on intermittent fasting combined with other interventions and 12hour fasting. Jamshed et al. (2022) evaluated the effectiveness of 12:12 intermittent fasting and
found that it resulted in a reduction in weight loss but not body fat. The study was conducted
with obese adults in Birmingham, Alabama. Hottenrott et al. (2020) combined intermittent
fasting with exercise and alkaline supplements. In both intermittent fasting and control groups,
alkaline supplements were associated with better performance running. The intermittent fasting
group was more effective in weight reduction (Hottenrott et al., 2020). These findings align with
other research findings on intermittent fasting and obesity.
The current research outlines the importance of intermittent fasting but is still deficient. Most
of the research focuses entirely on body fat and weight as key biomarkers. Research on other
biomarkers is scarce. Moreover, in most of the research articles reviewed, the studies were either
short-lived or had a small and non-generalizable sample. Some studies were either limited to
women or men which makes them hard to generalize to the public. Also, little research has been
conducted on other metabolic biomarkers such as blood pressure, glucose, and cholesterol.
Therefore, a gap exists in the research on intermittent fasting and its effectiveness in controlling
metabolic biomarkers. Filling this gap presents an opportunity to determine the efficacy of
intermittent fasting in reducing the rates of metabolic syndrome and conditions in the general
public.
Purpose of Study
The purpose of this study will be to determine the effectiveness of the intermittent fasting
16:8 method on decreasing metabolic biomarkers in overweight and obese individuals. The
research will determine whether intermittent fasting can reduce the risk of metabolic syndrome
in people who are already identified as overweight or obese.
Research Aims and Hypotheses
Aim: To determine the effectiveness of the intermittent fasting 16:8 method in reducing
metabolic biomarkers in overweight people.
Null Hypothesis: Compared to the maintenance of usual dietary habits intermittent fasting is not
associated with a significant change in metabolic biomarkers in overweight people.
Alternative Hypothesis: Intermittent fasting reduces metabolic biomarkers in overweight
people.
Definitions
Intermittent fasting: A dietary habit where the individual avoids any food intake for 16
hours per day and has an 8-hour window to eat (Cho et al., 2019).
Metabolic biomarkers: Biological indicators of inflammation that include waist circumference,
blood glucose, blood pressure, triglycerides, and cholesterol levels (Aleksandrova et al., 2018)
Overweight people: People who have a body mass index (BMI) of 25- 29.5 kg/m2
Delimitations and Limitations
The study will be limited to healthy members of the public who have not been diagnosed
with any chronic or terminal illness. It will also be limited to people aged between 18 and 65
years old (adults excluding older adults) with a BMI of 25 and above. The study will be limited
to people living in an urban center in the United States and those who can provide informed
consent and be available for follow-up. The main limitation of the study is that it may not be
generalized to other cities or countries due to the possible unique dietary habits of people in this
one city.
CHAPTER II
EVIDENCE ANALYSIS
A review of the literature on Intermittent Fasting for Improving Metabolic Biomarkers is
presented in the following evidence analysis tables. The quality of each study was assessed
along with the type of study, the demographics of the participants, the interventions, and major
research findings. In addition, each table delineates the strengths and limitations of each study.
The table was divided into subsections of the author, study design, participant details,
methodology, findings, and strengths and limitations.
Author and
Study
Participant
Method Details
Findings
Strengths and
location
Design
Details
Methods in your
Include all
limitations
Include first
Randomized
Number,
own words –
appropriate
Consider
author last
Control,
gender, age,
length of study,
outcomes, p-
population size,
name,
Experimenta
other identifiers
exact
values for
study design,
location (U.S,
l, Cross-
intervention
each and if it
participants,
Italy etc.) and
Sectional,
details, what
reached
length of study
include a
Cohort.
were they
statistical
etc.
superscript
Do not use
looking to
significance
citation
other
measure.
number.
systematic
reviews or
metaanalyses.
Jamshed, H.,
Randomized
Adults aged 25
Conducted
Among the 59
One strength of
Steger, F. L.,
clinical trial
to 75 years with
between August
completers, it
the study is that
Bryan, D. R.,
obesity and who
2018 and April
was discovered it collected
Richman, J. S.,
received weight- 2020
that eTRE+ER
firsthand
Warriner, A.
loss treatment
14-week study
was more
information
H., Hanick, C.
through the
Intervention
effective for
regarding the
entailed giving
losing body fat
experience of
J., & Peterson,
Weight Loss
participants
and trunk fat
the participants
C. M. (2022)
Medicine Clinic
weight loss
than CON+ER. regarding
We screened
treatment mainly
obesity and
656 people and
energy restriction
overweight.
enrolled 90
and it was
participants
randomized to
The limitations
eTRE plus ER
of the study is
and the control
short duration,
group for 8 hours
use of self-report
and more than 12
to assess patient
hours
condition.
respectively.
Cho, Y.,
Randomized
No participants
The method
The findings
One limitation
Hong, N.,
controlled
were involved
entailed selecting
show that after
is that the
Kim, K. W.,
trials and
because it was a
articles with
fasting for 12
studies used
Cho, S. J.,
controlled
secondary
periodic fasting,
hours lipolysis
were diverse,
Lee, M., Lee,
clinical trials
literature
periodic data, and
starts in the fat
which makes it
analysis
modified fating
tissues.
to have a broad
and evaluating the Skipping
scope that is not
trend in these
breakfast is
narrowed.
articles.
associated with
Y. H., & Lee,
B. W. (2019)
increased
stress.
Chobufo, M.
Cross-
5000 persons in
The methods
D., Gayam, V., sectional
15 counties per
entails conducting show that
that blood
Soluny, J.,
year.
a NHANES by
education level
pressure
the CDC. The
determined
readings were
Rahman, E.
study design
The findings
One strength is
U., Enoru, S.,
records helped to
one’s level of
done at the same
Foryoung, J.
get systolic and
hypertension.
time. One
B., & Nfor, T.
diastolic blood
Increasing age,
limitation is that
(2020)
pressure readings
obesity, being
two years’ time
of participants.
a man, and
period is very
those with
small or
diabetes were
studying
at risk of
changes in
hypertension.
habits.
Randomized
group of 45
The interventions
The findings
One limitation
Control
women over 60
entailed assessing
showed that
of the study is
years
and tracking the
the body mass
that it entailed
M., Pakosz, P.,
participants’ body
of the
few participants,
Bączkowicz,
composition and
experimental
which cannot
D., &
BMI. It also
group reduced
help in drawing
Sadowska-
entailed
by 2 kg.
reputable and
Krępa, E.
measuring the
Skeletal body
reliable findings.
(2020)
mental state and
mass did not
ankle-branchial
change
index.
significantly.
Domaszewski,
P., Konieczny,
Hales, C. M.,
Cross-
Adults aged 20
1999-2000
The study
One strength of
Carroll, M. D.,
sectional
and over
through 2015-
identified a
the study is the
2016
significantly
use of bulk
Ogden, C. L.
increasing
historical data.
(2020)
trend in obesity
Fryar, C. D., & study design
One limitation is
reliance on
historical data,
whose
authenticity and
reliability cannot
be determined
Aleksandrova,
Information is Both adults and
The time of the
The study
One strength is
K.,
from
children with
study is not
identified the
that the research
Mozaffarian,
secondary
obesity
specified as most
role of
is broad and
D., & Pischon,
sources
information is
biomarkers in
comparative.
from secondary
obesity related
One weakness is
sources
cases and their
that most of the
association in
information used
cardiometaboli
is not firsthand.
T. (2018).
c diseases.
Hottenrott, K.,
Clinical trials
80 overweight
All participants
The study
The advantages
Werner, T.,
subjects of age
were tested for 12
determined the
of this study are;
Hottenrott, L.,
45.5 ± 7.8 years
weeks
combined
It took a short
Meyer, T. P.,
effects of IF,
reasonable time
& Vormann, J.
exercise
and the data was
(2020).
training and
first hand hence
alkaline
very accurate.
supplementatio
n in
overweight
participants on
body
composition
and running
performance
Kunduraci, Y.
Randomized
Metabolic
E., & Ozbek,
controlled
H. (2020).
trial
12 weeks .
The study
One limitation is
syndrome
found out that
the study was on
patients, aged
technique used
metabolic
18–65 years in
to achieve
syndrome
Istanbul Turkey
energy
patients hence
restriction, in
hot giving
either
accurate data to
intermittent or
be used for
continuous,
healthy people.
alleviates the
metabolic
syndrome
biomarkers
activated by
weight loss.
Rynders, C.
Randomized
11 adults with
8 weeks
The available
one limitation of
A., Thomas, E. trials
overweight or
evidence
this research is
A., Zaman, A.,
obesity (BMI ≥
indicates that
that it uses few
Pan, Z.,
25 kg/m2)
Intermient
participants.
Catenacci, V.
Energy
A., &
Restrictions
Melanson, E.
paradigms
L. (2019).
cause equal
weight
reduction when
compared to
Continuous
Energy
Restrictions,
with no
changes in
weight or body
fat loss across
groups being
observed in 9
out of 11
studies
assessed.
Zouhal, H.,
Experimental
28 males with
Bagheri, R.,
method
obesity
30 days
The results of
One advantage
this study show of this study is
Ashtary-
that fasting
that it was
Larky, D.,
during
carried out
Wong, A.,
Ramadan
during a time
Triki, R.,
reduced
when fasting
Hackney, A.
systemic
was mandatory
C., &
inflammatory
hence increasing
Abderrahman,
biomarkers in
data accuracy.
A. B. (2020).
obese males
and there was
no detrimental
effects on the
indicators of
liver and renal
function.
Ogden, C. L.,
National
9120
Between 2003-
According to
The advantage
participants
2012 (10 years)
the
of this article is
Kit, B. K., &
study, there
that it used large
Flegal, K. M.
have been no
amount of data
(2014)
significant
Carroll, M. D., survey.
changes in
hence being
obesity
more accurate.
prevalence in
youth or adults
between 20032004 and
2011-2012.
Obesity
prevalence
remains high
and thus it is
important to
continue
surveillance.
Ravussin, E.,
Clinical trial
Meal-timing
One limitation
interventions
of this study is
Poggiogalle,
facilitate
that it took a
E., Hsia, D. S.,
weight loss
very short time
& Peterson, C.
primarily by
hence may be
M. (2019).
decreasing
inaccurate.
Beyl, R. A.,
11 overweight
4 days
adults
appetite rather
than by
increasing
energy
expenditure
Harvey, J.,
Randomized
Study 1; 44
6 months and 4
Howell, A.,
Clinical trials
women on
months
Morris, J., &
Intermittent
Energy
According to
this study,
intermittent
dieting could
be an effective
way to achieve
One limitation
about this study
is that it requires
Harvie, M.
Restrictions for
(2018).
6 months
Study 2; 72
women on two
weight loss
without having
to worry about
calorie
compensation.
more time for
The study
concluded that
High-calorie
breakfasts are
advantageous
and may be a
practical
substitute for
managing
obesity and
metabolic
syndrome at
dinnertime.
The advantage
From the
The advantage
credible results.
types of
Intermitent
Energy
Restrictions for
4 months
Jakubowicz,
Randomized
Overweight and
D., Barnea,
experiments
obese women
M., Wainstein,
(BMI 32.4 ± 1.8
J., & Froy, O.
kg/m2) with
(2013
metabolic
12 weeks
syndrome
85 obese women 12 months
of this study is
that it specific
on the research
population
hence its
findings are
useful for that
population.
Viegener, B.
Randomized
J., Renjilian,
controlled
study, the
about this study
D. A.,
trials
group that did
is that it
McKelvey, W.
intermittent
compares two
F., Schein, R.
fasting lost
populations over
L., Perri, M.
weight faster
different lengths
G., & Nezu, A.
than those that
of time.
M. (1990).
did regular
treatment.
Acosta-
Controlled
8-week-old male 2 weeks
From the
One limitation is
Rodríguez, V.
experiment
mice
study,
the time
A., de Groot,
concentrating
allocated was
M. H., Rijo-
their food
little hence can
Ferreira, F.,
intake and
be led to
Green, C. B.,
suddenly
inconclusive
& Takahashi,
boosting their
results.
J. S. (2017
wheel-running
activity during
the rest period,
mice under
Caloric
Restriction
self-imposed a
temporal
component,
exposing
previously
unappreciated
linkages
between
feeding,
metabolism,
and behavior.
Hoddy, K. K.,
Random trials 74 obese people
Gibbons, C.,
between the age
Kroeger, C.
of 25-65 years.
M.,
8weeks
These results
imply that the
effectiveness
of an 8-week
ADF regimen
One limitation
about this study
is that it is
Trepanowski,
J. F.,
Barnosky, A.,
Bhutani, S., …
& Varady, K.
A. (2016).
Julia, C.,
Cohort study
Péneau, S.,
46435 people
10 years
above 18 years
for weight loss
may be
influenced by
the absence of
a
compensatory
rise in hunger
along with an
increase in
fullness
sensations.
population
From the
One strength of
study, when
this research is
specific
Andreeva, V.
loosing weight, that it takes a
A., Méjean,
it is essential to long time, hence
C., Fezeu, L.,
maintain a
being more
Galan, P., &
dietary
accurate.
Hercberg, S.
balance.
(2014).
Horne, B. D.,
A systemic
Both male and
Literature from
There are few
Limitations of
Muhlestein, J.
review of
female
2015
literature
this research is
B., &
public
sources on the
that it is not
Anderson, J.
literature on
randomized
conclusive.
L. (2015).
randomized
clinical trials
clinical trials
hence need for
more research
Carter, S.,
Randomized
137 men and
Clifton, P. M.,
noninferiority
women with
type 2 diabetes, this research is
type 2 diabetes
intermittent
that it has
calorie
updated
& Keogh, J. B. trial
(2018
12 months
In patients with One strength of
restriction is
supporting
comparable to
evidence which
continuous
makes it valid.
energy
restriction in
terms of
effectiveness in
lowering
HbA1c.
CH III
METHODS
This systematic review was conducted based on the Preferred Reporting Items for
Systematic Reviews and Meta-Analyses (PRISMA) standards, which guides in the selection of
articles for use in information extraction. PRISMA helped in assessing, locating, and
incorporating the information that is available into the report. It is worth noting that the PICO
approach that entails the use of population, intervention, comparison, and outcome of treatment
intervention. The PICO approach helped to develop a model as outlined in the table below. The
study was used to determine the impact of intermittent fasting of about 12 to 16 hours could help
the obese and overweight to manage their weight. The impact of the intervention was traced
across several articles, which showed the impact of intermittent fasting on the metabolic activity
rate. The rate of effectiveness of intermittent fasting was evaluated among obese and overweight
individuals that participated in the studies. It is worth noting that the studies that were only
included were those that were obese or overweight with a BMI of 25 or above.
Throughout this systematic review, the flow diagram of PRISMA located below,
determined the guidelines and workflow that was used to analyze and review each piece of
literature. The flow diagram also contains information about how each piece of literature was
incorporated into this review in terms of locating, assessing, and appropriateness. Research
studies that fell under the categories of either meta-analyses or systematic reviews were used to
find material or data that was capable of meeting the criteria of inclusion. However, metaanalyses and systematic reviews were not included in finding necessary data or information for
inclusion and were excluded from this review.
The core search terms used in the systematic review include “obese”, “obesity”,
“intermittent fasting”, “dieting,” fasting and many others. The major databases that were used
include PubMed, Google Scholar, and the Cumulative Index to Nursing and Allied Health
Literature (CINAHL).
The research articles that were used in this review had to meet the standards in The
Academy of Nutrition and Dietetics (AND) Quality Criteria Checklist for Primary Articles. For
studies that passed the checklist, the studies were incorporated into the Academy of Nutrition
and Dietetics (AND) Evidence Analysis Table (Chapter 2). The tables outlined each research
study and summarized the outcomes. It is worth noting that the tables provided a methodical
arrangement of each research study by outlining the author(s), year of publication, sample
characteristics, treatment and control groups, intervention/exposure examined, results, and
strengths and limitations.
PICO Inclusion Criteria
PICO
Potential Search Terms
Population:
Those with obesity and overweight (of BMI 25 or above)
Intervention:
Intermittent fasting for 8-16 hours.
Comparison (you may not
have):
Those not fasting but following a hypocaloric diet
Outcome(s):
Reduced body weight and BMI.
Search Terms Used for Systematic Review and Evidence Analysis
Database
Date of search
Search String
Filters Used
Numb
er of
result
s
Numb
er of
result
s after
remov
ing
duplic
ates
After
reviewin
g for
quality,
articles
kept
PubMed
4-June-23
“overweight”,
“obese” and
intermittent fasting
5 years, clinical
trial, randomized
controlled trial
36
34
21
Google
Scholar
5-June-23
“overweight”,
“obese” and
intermittent fasting
5 years, clinical
trial, randomized
controlled trial
22,700
11,470
15
CINAHL
15-June-23
“overweight”,
“obese” and
intermittent fasting
5 years, clinical
trial, randomized
controlled trial
97
80
9
Methods
PRISMA 2009 Flow Diagram
Records identified through
database searching
(n = )
Additional records identified
through other sources
(n = )
Records after duplicates removed
(n = )
Records screened
(n = )
Records excluded
(n = )
Full-text articles assessed
for eligibility
(n = )
Full-text articles excluded,
with reasons
(n = )
Studies included in
qualitative synthesis
(n = )
Studies included in
quantitative synthesis
(meta-analysis)
(n = )
Id
e
nt
ifi
c
S
cr
e
e
ni
Eli
gib
ilit
y
In
cl
u
d
e
References
Acosta-Rodríguez, V. A., de Groot, M. H., Rijo-Ferreira, F., Green, C. B., & Takahashi, J.
S. (2017). Mice under caloric restriction self-impose a temporal restriction of food
intake as revealed by an automated feeder system. Cell metabolism, 26(1), 267-277.
Aleksandrova, K., Mozaffarian, D., & Pischon, T. (2018). Addressing the perfect storm:
Biomarkers in obesity and pathophysiology of cardiometabolic risk. Clinical
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Carter, S., Clifton, P. M., & Keogh, J. B. (2018). Effect of intermittent compared
with continuous energy restricted diet on glycemic control in patients with type 2
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