the Effect of Diet Intervention on Obesity
Phase: NA
Conditions: Obese, Stomach Diseases
Sponsor: Zhang Manna

Study protocol 
 
 
 
 
 
 
 
Project name: diet intervention in obesity-related complication 
Solution Version Number/Date: 1.0/2024-6-23 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Research background 
Obesity has become a World epidemic disease. According to the latest "World Obesity Map" 
[1] released by the World Obesity Federation in 2023, it is expected that by 2035, more than 
4 billion people in the world will be overweight or obese, accounting for more than half of 
the total population. Obesity-related complications are responsible for 4 million deaths per 
year worldwide, accounting for 7.1% of all-cause deaths [2]. Obesity-related complications, 
including diabetes, Metabolic associated Fatty Liver Disease (MAFLD), hyperlipidemia and 
other metabolic diseases listed in the Clinical Practice Guidelines for the Integrated 
Management of Obese Patients published by the American Association of Clinical 
Endocrinologists, And stress osteoarthritis, stress urinary incontinence, gastroesophageal 
reflux disease and other volume-load-related diseases [3]. Obesity is also closely associated 
with gastric mucosal injury diseases, such as gastric ulcer and gastric cancer. 
A series of previously published studies suggest that obesity, especially centripetal obesity, is 
an independent risk factor for gastric ulcer [4]. A large retrospective cohort study with 226,953 
participants found that there was a statistically significant difference in the incidence of gastric 
ulcer among people with different Body Mass Index (BMI) cut-off points, and BMI>25 kg/m2 
was an independent risk factor for gastric ulcer [5]. Another prospective cohort study 
suggested that obese patients with BMI≥30.0 kg/m2 had an 83% increased risk of gastric 
ulcer compared with normal BMI. Compared with men with a Waist to Hip Ratio (WHR) of 
0.85-0.89, men with a WHR≥1.00 also had an 88% increased risk of gastric ulcer [6]. In 
addition, many studies have revealed the relationship between obesity, precancerous lesions 
of gastric mucosa and gastric cancer [7]. A retrospective study [8] found that the risk of 
Intestinal Metaplasia (IM) in overweight and obese patients increased by 72% and 141%, 
respectively. A large epidemiological investigation study on global lifestyle and risk of 
gastrointestinal tumors published in 2021 showed that BMI was positively correlated with the 
prevalence of gastric cancer [9]. In addition, a meta-analysis of 3,097,794 subjects (including 
9,492 patients with stomach cancer) found that obese patients had a 36% increased risk of 
stomach cancer compared to people with normal BMI [10]. Another meta-analysis of 10 
prospective studies and 12 case-control studies confirmed that each 2.5 kg/m2 increase in 
BMI was associated with an 11% increased risk of gastric cancer. The risk of gastric cancer in 
overweight and obese patients increased by 71% and 134%, respectively [11]. Therefore, 
obesity-related gastric mucosal injury, as an important complication of obesity, needs urgent 
attention in clinical and basic research fields. It is of great significance to study the mechanism 
of obesity-related gastric mucosa injury for reducing the risk of obesity-related gastric cancer. 
[1] <Obesity Atlas 2023 _ World Obesity Federation Global Obesity Observatory.pdf>. 
[2] Reilly JJ. Health effects of overweight and obesity in 195 countries over 25 years[J]. 
N Engl J Med. 2017;377(15):1496. 
[3] Garvey WT, Mechanick JI, Brett EM, et al. American association of clinical 
endocrinologists and american college of endocrinology comprehensive clinical practice 
guidelines for medical care of patients with obesity[J]. Endocr Pract. 2016;22 Suppl 3:1-203. 
[4] Sogabe M, Okahisa T, Kimura T, et al. Influence of metabolic syndrome on upper 
gastrointestinal disease[J]. Clin J Gastroenterol. 2016;9(4):191-202. 
[5] Garrow D, Delegge MH. Risk Factors for Gastrointestinal Μlcer Disease in the US 

Population[J]. Digestive Diseases & Sciences. 2010;55(1):66-72. 
[6] Boylan MR, Khalili H, Huang ES, et al. Measures of Adiposity Are Associated With 
Increased Risk of Peptic Μlcer[J]. Clinical Gastroenterology & Hepatology the Official 
Clinical Practice Journal of the American Gastroenterological Association. 2014;12(10). 
[7] Avgerinos KI, Spyrou N, Mantzoros CS, et al. Obesity and cancer risk: Emerging 
biological mechanisms and perspectives[J]. Metabolism. 2019;92:121-135. 
[8] Kim N, Youn CH, Kim AS, et al. Associations between Body Mass Index and Chronic 
Atrophic Gastritis and Intestinal Metaplasia[J]. Korean J Gastroenterol. 2017;70(2):81-88. 
[9] Lu L, Mullins CS, Schafmayer C, et al. A global assessment of recent trends in 
gastrointestinal cancer and lifestyle-associated risk factors[J]. Cancer Commun (Lond). 
2021;41(11):1137-1151. 
[10] Yang P, Zhou Y, Chen B, et al. Overweight, obesity and gastric cancer risk: results 
from a meta-analysis of cohort studies[J]. Eur J Cancer. 2009;45(16):2867-2873. 
[11] Turati F, Tramacere I, La Vecchia C, et al. A meta-analysis of body mass index and 
esophageal and gastric cardia adenocarcinoma[J]. Ann Oncol. 2013;24(3):609-617. 
 
 
Research purpose 
Main Purpose 
 To investigate the effect of 12-week dietary intervention on gastric mucosal damage in 
adult obese patients 
Secondary Purposes 
 To evaluate the effects of 12-week dietary intervention on glucose metabolism, lipid 
metabolism and thyroid metabolism in obese patients 
 To evaluate the effects of a 12-week dietary intervention on the liver of obese patients 
 
Study endpoint 
Primary end points 
 Changes in body weight (Kg) and gastric injury from baseline 0 to 12 weeks 
Secondary endpoints 
 glycolipid metabolism and thyroid function 
 Fatty liver 【 Liver function indicators, liver tumor indicators, liver fat content and hardness 
values, improvement of liver enlargement or fatty liver 】 
 
Research design 
This clinical study was a 3-month prospective, single-center trial. Obese adults aged 18-65 
years were recruited. After signing the informed consent, patients meeting the 
inclusion/exclusion criteria who completed baseline clinical visits and data collection were 
randomly assigned 1:1 to the intervention group (n=30). The intervention group was treated 
with low LA diet pattern for 12 weeks. 
 
Intervention measure 
Low LA nutritional diet description: The fat intake is mainly unsaturated fatty acids (such as 
linseed oil, olive oil, etc.), and the diet structure includes a diet containing fruits, vegetables 

and grains, fish, shrimp and seafood, poultry and eggs. Cooking dishes using olive oil, reduce 
the intake of LA, can eat a moderate amount of nuts; Eat a small or moderate amount of 
yogurt or cheese every day; Appropriate intake of fish, shrimp and seafood; Eat eggs; During 
the intervention period, try not to consume red meat (cattle, sheep, pork); Drink the right 
amount of water every day. 
 
Intervention process 
1. For 12 weeks, the intervention group used olive oil for cooking, caloric restriction, 1300Kcal 
for women and 1600Kcal for men. A trained professional dietitian evaluates the menu weekly 
to limit LA intake. 
2.At baseline visits, trained physicians conducted face-to-face interviews using standard 
questionnaires to obtain information on demographic attributes, lifestyle factors, health status 
and drug use. 
3. Study participants were asked not to change their physical activity and to continue their 
chronic medications unless modified by their personal physician. 
4. To help improve adherence to allowable caloric intake, all participants received dietary 
counseling throughout the duration of the trial. Dietary counseling is conducted under the 
guidance of a trained nutritionist. Participants received a written diet information brochure 
with some suggestions and sample menus. 
5. At the beginning of the intervention, each participant was trained. The patients self-
measured their fasting weight every day and recorded their sleep, step count and dietary 
adaptation. 
6. Participants received weekly online healthy eating promotion training to guide them on 
how to firmly specify their diet for a long time, ensure the quality of their diet, and avoid 
overeating when they eat freely, to assess participants' adherence to the program and help 
participants achieve their caloric goal of weight loss within 3 months. 
7. The participants measured their neck circumference, waist circumference and hip 
circumference at the end of each week and gave feedback on their eating situation. 
8. in week 4 and week 8, the subjects were followed up in the outpatient department for 
biochemical examination, in body test, face-to-face communication with doctors to evaluate 
the effect of weight loss. 
9. At baseline and at week 12, gastric tissue specimens were collected for gastric injury 
assessment. 
10. Compliance is assessed by dividing the number of meals served by the number of meals 
served. 
11. Physical examination, biochemical and imaging examinations were performed on all 
participants at the 12th week. 
 
Subject population 
The inclusion criteria were: 
(1) Men and premenopausal women, aged 18-65 years at the time of signing the informed 
consent 
(2) Obese patients were diagnosed based on body mass index (BMI) 28-40kg/m2 
2. Exclusion criteria are: 

1）Patients who do not have or lose the ability to make autonomous judgments, do not 
understand the purpose of the study, or are unwilling to cooperate; 
2) Heart, liver, kidney dysfunction and systemic diseases, such as various malignant tumors, 
systemic allergic diseases, autoimmune diseases; 
3）Drug or alcohol dependence, intellectual disability, mental disorders; 
4）Pregnant and lactating women; 
5) Confirmed Helicobacter pylori infection (PPI, bismuth and antibiotics were stopped for at 
least 4 weeks, and any of the following tests were positive: non-invasive Hp test such as urea 
breath test, monoclonal stool Helicobacter pylori antigen test, serum soluble Helicobacter 
pylori antigen test; Invasive Hp test included rapid urease test and tissue section staining); 
6）diagnosis of acute gastric mucosal lesions; 
7）According to the Consensus Opinion on Chronic Gastritis in China in 2017, the patient was 
diagnosed with chronic gastritis according to the new Sydney system visual simulation scoring 
method and the pathological diagnostic criteria of chronic gastritis in China; 
8）Patients with gastroscopy and histological pathology who meet the diagnostic criteria for 
gastric ulcer  
9）the Diagnosis and Treatment of Gastric Cancer, combined with endoscopic, histological 
and imaging examinations, adenocarcinoma was diagnosed 
 
Termination criteria 
Discontinue use of the test product in any of the following cases: 
 The subject requests withdrawal of informed consent 
 Inclusion in trials that violated inclusion and/or exclusion criteria and/or randomization 
criteria 
 Safety concerns are at the discretion of the investigators 
 Subjects will not tolerate serious adverse events 
 Excessive alcohol consumption (>70 g/wk) and smoking habits 
 Diagnosed with cancer, kidney disease or diabetes, lactose intolerance 
 Pregnant or trying to get pregnant 
 To participate in a clinical trial of another approved or unapproved investigational drug 
product 
 
Research process 
Screening period 
 Potential participants were recruited through advertising 
 All subjects are required to complete relevant screening tests before enrollment and be 
screened according to the admission criteria 
Sc/Rz (Screening period) related content is as follows: 
 sign informed consent; 
 Demographic characteristics: sex, age 
 Medical history: including past medical history and drug use history 
 Physical examination: height and weight 
Baseline Period 
 V0 (baseline period) : Subjects who meet the inclusion criteria and do not have exclusion 

criteria can be directly enrolled. 
V0 (baseline period) related content is as follows: 
 Physical examination: height and weight 
 Laboratory tests: glucose metabolism, lipid metabolism, thyroid function, liver and kidney 
function 
 Laboratory examination: liver and kidney function, glucose metabolism, lipid metabolism 
 Imaging examination: hardness data ultrasound 
 24 hour Dietary Review Scale 
 Gastric tissue assessment of gastric injury 
 Participants were provided with a written dietary information brochure containing some of 
the recommendations and sample menus  
Intervention Period 
 Record the daily diet, collect and analyze the diet according to the weekly diet recall table. 
 in week 4 and week 8, the subjects were followed up in the outpatient department for 
biochemical examination, in body examination, face-to-face communication and evaluation 
with doctors 
 Participants' fasting weight was measured every morning, and the number of meals, eating 
time, eating feelings, sleep and step count were recorded. 
 The adverse reactions and severity during the intervention were recorded. 
 Healthy diet publicity and education: Online healthy diet training will be conducted once 
a week to promote regular and quantitative eating, avoid overeating, and ensure diet quality. 
Endpoint Period (Week 12) 
measurement same as base line 
 
Statistical methods 
Sample size estimation 
It has always been a very important link in clinical trials to select research objects through 
random sampling technology to determine what sample size is representative. Sample size 
estimation is related to the reliability, repeatability and efficiency of the research results, which 
reflects the balance between clinical significance and statistics. In any study, it is impractical 
to study the population as a whole. Sample size refers to the minimum number of test units 
(study individuals) determined by corresponding statistical methods under the premise of 
ensuring the reliability of research conclusions. In the actual research process, a group of 
participants is selected from the population. This group of participants can not only weigh all 
aspects of the trial to ensure the efficiency of the test, but also fully represent the overall 
population, and draw a conclusion for the overall population according to the final test results. 
Therefore, sample size estimation is one of the key links of clinical trials. 
Statistically speaking, the main parameters that affect the sample size are: Class I error α, Class 
II error β or certainty of the experiment (1 to β), tolerance error γ, and population correlation 
information. Three factors are often considered in optimal parallel randomized controlled 
trials, namely, the size of the difference between the experimental intervention and the control 
intervention, the requirement for the accuracy of the trial, and the compliance of the test 
subjects. The sample size is calculated as follows: 

 
Where, n is the required sample size for each group, u1 is the basic measurement value, u2 
is the measurement value to be reduced, σ is the standard deviation, f(α, β) is a constant, 
which can be obtained by looking up the table according to the difference between α and β. 
In test reports with explicit formulas, researchers often set Class I error α to 0.05 and Class II 
error β to 0.2. These parameters were originally set to avoid the problem of false positives 
and false negatives, and are not set in stone, but there are few reports to adjust the size of 
the parameters according to the actual situation. 
Relevant parameters: In general, sample size estimates are closely related to the target disease. 
Combined with the target disease of the test, the size of class I error α and class II error β are 
appropriately adjusted to ensure that the β is as small as possible when the α is sufficiently 
small, so as to maintain the rejection of H0 and not make big mistakes. At the same time, it is 
necessary to clarify the relevant values of target diseases and target drugs. Such as: standard 
deviation σ, tolerance error γ, etc. 
Compliance: For clinical trials, the shedding rate refers to the proportion of cases that failed 
to complete the trial according to the trial design after enrollment. For RCT, the shedding rate 
refers to the number of people who fail to complete the test. The total sample size required 
for the trial was 2n/(1-10%) with 10% dropout or loss of follow-up considered. 
· Calculation process: 
A randomized controlled study was conducted to investigate plant-based diet intervention in 
obesity. Patients were divided into treatment group and control group (no intervention group) 
by completely randomized method. The main outcome indicator was the weight change of 
obesity after intervention. 
The sample size was determined according to the weight change in the previous pre-
experiment, and the weight index was a continuous variable. The average weight of the 
control group was expected to be 80.31±15.63 (before intervention), and the weight of the 
intervention group was expected to be reduced by 3.67±2.42 after the plant-based diet. For 
bilateral test, α was 0.05, the ratio of sample size between the two groups was 1:1, and the 
certainty (test efficiency) was 1-β=90%. PASS15 software was used to calculate the required 
sample size. 
 
Safety monitoring, reporting and medical treatment 
Definition of Adverse Events (AE) 
An adverse event is any adverse medical event that occurs after a patient or subject receives 
a drug that is not necessarily causally related to the treatment. Therefore, an adverse event 
can be any adverse physical sign (including abnormal laboratory results), symptom, or disease 
that has a time correlation with the use of the investigational drug, regardless of whether a 
causal relationship with the investigational drug is considered. Adverse events include Serious 
adverse events (SAE) and non-serious adverse events. 
SAE Definition 
SAE refers to the occurrence of medical events during clinical trials that require hospitalization 
or prolonged hospitalization, disability, affect work ability, endanger life or death, and lead to 

congenital malformations. Includes the following medical events: 
1) events leading to death; 
2) life-threatening events (defined as subjects in immediate danger of death at the time of 
the event); 
3) Events requiring hospitalization or prolonged hospitalization; 
4) Events that can cause permanent or severe disability/disability/affect the ability to work; 
5) Congenital abnormalities or birth defects; 
Other medically important events (defined as events that endanger subjects or require 
intervention to prevent the occurrence of any of the above). 
Adverse event recording, collection, reporting and handling 
Collection and recording of AE 
All aes that occur between the signing of the informed consent and the provision of the plant-
based diet should be recorded in the CRF table. 
The record of the AE should include: description of the AE and all associated symptoms, time 
of occurrence, severity, duration, correlation with the test food, action taken, and final 
outcome and outcome. The recording of AE must use medical terminology, and if the 
subject's signs and symptoms can be summarized by a common cause, the diagnosis should 
be recorded as far as possible. In addition to indicators related to disease progression, all 
clinical events and clinically significant laboratory adverse events can be treated with reference 
to the Common Adverse Event Evaluation Criteria (CTCAE) version 5.0. Adverse reactions to 
treatment will be recorded by the investigator. 
Pregnancy 
Women who are fertile should use an effective contraceptive method for the period specified 
in the study. Before recruiting fertile women into the study, researchers must inform women 
of childbearing age about the importance of avoiding pregnancy during study participation, 
as well as potential risk factors for unwanted pregnancies. Subjects must sign informed 
consent forms to show that the issues have been discussed and fully understood. 
Pregnancy test requirements: Urine pregnancy test results must be negative for all fertile 
women during screening, baseline, and treatment. In addition, all fertile women should be 
advised to report a possible pregnancy (such as menopause or delayed menstruation) to the 
investigator immediately at any time during the trial. 
Pregnancy reporting: If pregnancy or suspected pregnancy is found during trial administration, 
the study drug should be discontinued. 
Criteria for judging AE severity 
Researchers will evaluate severity according to the five-level criteria developed by the NCI 
CTCA version 5.0: 
Grade 1, mild; Asymptomatic or with mild signs; For clinical or diagnostic observation only, 
without medical intervention; 
Grade 2, moderate; Age-appropriate limited functions of daily living (such as cooking, 
shopping, making phone calls, etc.); 
Level 3, serious or medically important but not immediately life-threatening; Resulting in 
hospitalization or prolonged hospitalization; Disability; Limited daily self-care activities (daily 
self-care activities refer to bathing, dressing, undressing, eating, toilet use, medication, etc., 
but not bedridden); 

Level 4, life-threatening, requiring urgent medical treatment; 
Level 5, AE-related death; 
Other responsibilities of investigators during follow-up of serious adverse events 
Serious adverse events should be examined and treated according to clinical judgment, 
including necessary clinical laboratory examination and physical examination. The results of 
any inspection or other updated SAE-related information obtained must be reported in a 
follow-up report within the same time frame and process as the initial report. 
Test termination/suspension criteria 
Sponsor 
reserves 
the 
right 
to 
terminate/suspend 
this 
experiment. 
Before 
terminating/suspending a clinical trial, the sponsor must notify the investigator, the Ethics 
Committee and the State Food and Drug Administration and state the reasons. After the early 
termination/suspension of the study, the restart of the study must be reviewed and approved 
by the Ethics Committee; 
Provision to end clinical trials 
The trial ends when all subjects meet the following conditions: 
1) All subjects completed 13-month clinical study and follow-up; 
2) or the death, loss of follow-up, or withdrawal of informed consent of all subjects. 
14. Data management 
Data Management 
1) The researcher must ensure that the data is true, complete and accurate; 
2) When any correction is made to the test record, the revised data can only be underlined, 
annotated by the margin, and the reason should be stated. The original record should not be 
erased or overwritten. 
3) Complete laboratory inspection items. 
Data recording and file saving 
Subject data on the case report form should be recorded in subject code and subject can only 
be identified by subject code or their initials. 
According to the requirements of the study protocol, the researcher shall fill in the collected 
data in a timely, complete, correct and clear Case Report Form (CRF), and send the signed 
CRF to the clinical research data manager in a timely manner. The corresponding database 
system is used for two-person and two-machine input, and then the database is compared 
twice. During the period, if any problem is found, the inspector is notified in time and the 
researcher is asked to answer. The exchange of questions and answers between them shall 
be in the form of a question table, which shall be kept for future reference. All steps involved 
in data management are documented so that data quality and test execution can be checked; 
After all the CRFS have been entered and verified correctly, the data manager will write out 
the database inspection report, which includes the study completion status (including the list 
of dropped subjects), inclusion/exclusion criteria check, integrity check, logical consistency 
check, outlier data check, time window check, etc. 
At the audit meeting, the main researcher, the representative of the bidding unit, the 
ombudsman, the data administrator and the statistician will make a decision on the informed 
consent signed by the subjects and the problems raised in the database inspection report, 
write the audit report, and the database will be locked at the same time. 
After completing data entry and verification as required, CRF shall file and save the data in 

numbered order, and fill in the retrieval catalog for reference. Electronic data files, including 
databases, inspection programs, analysis programs, analysis results, code books and 
explanatory files, etc., should be saved separately, and there are multiple backups saved on 
different disks or recording media, properly stored to prevent damage. All original files shall 
be kept for the period specified accordingly.