Impactul obiceiurilor alimentare asupra nivelului HbA1C: studiu privind tiparele de consum al alimentelor bogate în amidon şi de tip fast-food

Introduction

Type 2 diabetic mellitus (T2DM) is a worldwide known metabolic disorder, and its prevalence has been increasing rapidly. T2DM is characterized by hyperglycemia and, in late presentations, with vascular and neuropathic complications⁽¹⁾. This disease has an important association with a hormonal deficiency known as insulin deficiency. This may also be due to insulin resistance and type 2 diabetes, which are linked to both irreversible risk factors such as age, genetics and ethnicity, and reversible ones like diet, physical activity and smoking⁽²⁾.

Diet plays a crucial role in maintaining optimal health, particularly in regulating blood sugar levels, which directly impacts the risk of diabetes. HbA1C, a blood test that measures the average level of blood glucose over the past two to three months, serves as a key indicator of diabetes risk and its management⁽³⁾. The consumption of specific food groups, especially starch-rich foods and fast foods, has been widely discussed for its effects on insulin resistance and blood glucose control. A growing body of evidence suggests that diets high in processed foods, refined carbohydrates and sugars can increase the risk of developing type 2 diabetes due to their impact on blood sugar regulation⁽⁴⁾.

In this study, the relationship between HbA1C levels and the frequency of consumption of starch-rich foods (like rice, pasta, bread and potatoes) and fast food (which is typically high in unhealthy fats, sugars and refined carbohydrates) was examined. The previous study from the survey provides insight into how dietary habits influence blood glucose control. For example, a higher proportion of participants who rarely consumed starch-rich foods (only once a month) were found to have normal HbA1C levels, suggesting better blood sugar management. In contrast, those who consumed starch-rich foods more frequently (e.g., daily or several times a week) had higher HbA1C levels, indicating that regular consumption of these foods may be linked to poor blood sugar control and an increased risk of diabetes.

Similarly, other studies revealed that participants who rarely consumed fast food (once a month) were more likely to have normal HbA1C levels, while those who used to eat fast food more frequently (e.g., daily or several times a week) showed higher levels of HbA1C, further suggesting an association between frequent fast food consumption and poor blood sugar regulation. This underscores the importance of dietary choices in influencing overall health, particularly in the context of diabetes prevention and management.

By analyzing these dietary factors, this study aims to provide valuable insights into the impact of eating habits on long-term blood sugar control and diabetes risk, offering potential guidance for healthier eating patterns that could mitigate the risk of diabetes.

Methodology

Research approach and design

In this study, we used self-administered questionnaire as a data collecting tool to generate numerical data and statistical analysis to organize data. Therefore, the quantitative approach is the most suitable method for this study. The benefits of quantitative research are represented by the fact that it can gather empirical evidence that is rooted in objective reality and it can obtain significant accuracy through measuring physiological phenomena.

Research setting

The study setting was the diabetic clinic at Teaching Hospital Karapitiya (THK) in Sri Lanka. Teaching Hospital Karapitiya is the largest government hospital in the Galle district, located in Karapitiya, Sri Lanka. It is a teaching-oriented hospital that maintains a bed strength of 2500 and around 4500 staff involved in patient care. It provides treatment for about 250,000 inward patients and 800,000 outpatients per year. It covers most of the tertiary specialties and is properly equipped to treat the patients and provide the best training for students. It provides outpatient care in various clinic settings such as the diabetes clinic. The diabetes clinic of THK was the research setting according to the feasibility of the study team. There are about 10,500 patients registered in the diabetes clinic of THK, and the clinic was conducted from 8.00 a.m. to 4.00 p.m. in every weekday, except Sunday. There are six medical officers working under an endocrinologist supervision. Moreover, four nursing officers, nutritionist and healthcare assistants were also allocated to that unit.

Population and sample

The sample was represented by female patients who have registered in the diabetes clinic of the Teaching Hospital Karapitiya. The patients were selected to this study using simple random sampling technique. Researchers got the list of female clinic attendees with T2DM from the clinic register at diabetes clinic of THK. A total of 300 participants were selected – one in every three patients according to clinic register. Simple random sampling method was used.

Lawanga & Lame equation (1991):

N = required minimal sample size

Z = 1.96; critical value of specified confidence at 95% confidence interval

P = probable estimate of proportion of given characteristic

d = degree of accuracy desired set as 0.06.

Since no previous prevalence study on factors affecting glycemic control among women had been carried out in Sri Lanka, the anticipated population proportion was taken at 50% (N=294). The sample size (N) was rounded to 300 participants.

Inclusive and exclusive criteria

Female patients who have registered in the diabetes clinic at THK with diagnosed T2DM more than two years, with ages between 30 and 65 years old, were included. Critically ill patients and cognitive impaired patients were not included.

Data collection method

Data collection is a systematic process of gathering, measuring and analyzing information to address research objectives and answer specific questions. It involves selecting appropriate tools and techniques, such as surveys, interviews, observations or experiments, based on the nature of the study and the type of data required (qualitative or quantitative). A well-designed data collection method ensures accuracy, reliability and validity while minimizing biases. The process typically includes defining the research population, developing instruments, piloting tools, and implementing the method while adhering to ethical standards to protect participants’ confidentiality and integrity. In this study, we used simple random sampling technique.

Data collection instruments and tools

The data were collected using both self-administered questionnaire and biochemical laboratory reports. Questionnaire consisted of three sections to be filled by patients. The sociodemographic data were included into part A. Part B included questions regarding dietary factors, using food frequency questionnaire. Part C included questions regarding psychological factors that assessed depression, anxiety and diabetes-related distress. The last HbA1c level was filled by researchers.

Validity and reliability

The questionnaire was developed by researchers. Its reliability was assessed with 10 participants using the test-retest method, and consistency was evaluated using Cronbach’s alpha.

Data collection

Prior to conducting the main research, the scholars obtained approval from the Faculty of Medicine of the University of Ruhuna. All the research studies, data collections and data presentations were done purely with the university’s knowledge and administration. After that, there were personal discussions with each patient who wanted to participate in the research, and they were handed over the questionnaire. A total of 300 patients were given the questionnaire to collect data, and 297 responses were received.

Ethical considerations

For this study, the ethical approval for the study was obtained from the Ethical Review Committee of the Faculty of Medicine, University of Ruhuna. An information sheet was distributed among the subjects, containing purpose, objectives, risks and benefits of the study. A serial number was allocated to each questionnaire, distributed among each participant to assure the anonymity. The participants who wished to participate in the study were permitted to withdraw from the study at any time. The data were stored under password protected file with restricted access only to the main investigator and other members. Data were used for research purpose only. The hard copies of data were retained under lock and key for five years.

Data analysis

Data were entered, managed and analyzed using the MS Excel and the Statistical Package of the Social Sciences (SPSS) software version 21. Data from complete questionnaires were entered into MS Excel and SPSS. The reliability of the questionnaire was checked using the Cronbach’s alpha test. Data analysis was conducted both descriptive and using inferential statistics, to present the results of the study. Demographic characteristics were analyzed with the use of descriptive statistics, such as mean, median, mode, standard deviation and frequencies. The results were summarized and presented by tables and charts. SPSS software and Microsoft Excel were used as the tools for statistical and the graphical analysis.

Results

Data collection was done by self-administered questionnaire, with 300 participants selected from the Teaching Hospital Karapitiya, Sri Lanka, and 297 responses were given. All of them were female clinic attendees with T2DM from the clinic register at the diabetes clinic of the Teaching Hospital Karapitiya, Sri Lanka.

Table 1 presents the findings of a survey examining various dietary habits of respondents. It reveals that, when it comes to skipping breakfast, the majority (36%) never skip it, while a significant portion (31.3%) used to skip breakfast sometimes, and a smaller percentage either usually (11.4%) or rarely (21.2%) missed the first meal of the day. Regarding adherence to eating plans recommended by dieticians or nutritionists, nearly half (46.5%) followed these plans usually, with 39.4% doing so sometimes, while only a few (4%) never followed the recommendations.

In terms of sugar consumption, most respondents (59.6%) used to add sugar to their tea, while fewer used it in coffee (23.9%), juice (12.8%), or carbonated drinks (3.7%). When it comes to staple foods, a large percentage (78%) used to eat rice daily, followed closely by those who consumed vegetables daily (78%), indicating the importance of these foods in the respondents’ diets. The consumption of protein sources like fish, meat or eggs is more varied, with 48% eating them 3-4 times per week and 37% daily. Regarding fruits, 51% used to consume them 3-4 times a week, while 34% used to eat them daily.

Green leafy vegetables were also commonly consumed, with 39% eating them 3-4 times a week and 36% daily. Cereal consumption was more sporadic, with 33% consuming them 3-4 times per week, and 18% eating them daily. Dairy consumption follows a similar pattern, with 40% consuming milk or dairy products 3-4 times per week and 11% daily. Fiber-rich foods were eaten regularly by some, with 37% consuming them 3-4 times a week, but only 10% eating them daily. Starch-rich foods were consumed by 42% of the subjects 3-4 times per week, with 20% eating them daily.

Pulses were consumed more sporadically, with 39% eating them twice a month and 23% weekly. Fast food was consumed by 28% of respondents daily, with 32% eating 3-4 times per week. For sweet snacks, 36% indulged 3-4 times a week, and 11% used to eat them daily. Fruit juice consumption was less frequent, with 49% drinking it only once a month and 26% consuming it twice a month. Overall, the survey provided a detailed snapshot of dietary habits, highlighting common consumption patterns, such as regular intake of rice, vegetables and proteins, while also showing the infrequent consumption of certain items like fruit juice and pulses.

Figure 1 illustrates the relationship between HbA1C levels and the frequency of consuming starch-rich foods among survey participants. HbA1C is a marker used to assess blood sugar levels over a prolonged period, which helps in diagnosing diabetes and monitoring its management. We provide a more detailed interpretation.

The figure suggests that a higher proportion of participants who consumed starch-rich foods once a month had normal HbA1C levels (94%). This indicates that those who rarely consumed starch-rich foods were more likely to maintain healthier blood sugar levels. The term “starch-rich foods” refers to foods high in carbohydrates, such as bread, pasta, rice and potatoes.

On the other hand, the figure highlights that individuals who consumed starch-rich foods more frequently – specifically, those who used to eat them daily, 3-4 times per week, once a week, or twice a month – had a higher prevalence of diabetes or abnormal HbA1C levels, implying they were more likely to suffer from diabetes or were at a higher risk.

This suggests a potential association between frequent consumption of starch-rich foods and an increased likelihood of higher blood sugar levels, which could contribute to the development of diabetes or make it harder for people to manage the condition.

Figure 2 examines the relationship between HbA1C levels and the frequency of fast food consumption among survey participants. As with Figure 1, HbA1C levels are used to assess long-term blood sugar control, providing insight into the potential risk of diabetes or other metabolic conditions.

From the figure, it is obvious that a higher proportion of participants who used to eat fast food once a month had normal HbA1C levels (88%), indicating that those who consumed fast food very infrequently were more likely to maintain healthy blood sugar levels. This could suggest that a less frequent intake of fast food may be beneficial in maintaining overall metabolic health, including normal blood sugar levels.

However, the figure also shows that participants who consumed fast food more frequently – such as 3-4 times per week, twice a week, once a week, or twice a month – were more likely to have abnormal HbA1C levels, suggesting they were suffering from diabetes. This trend points to an increased risk of developing or having diabetes among those who consume fast food regularly. Fast food is typically high in refined carbohydrates, sugars and saturated fats, all of which can contribute to insulin resistance and increased blood sugar levels, both of them being linked to diabetes.

Thus, the comparison highlights that frequent fast food consumption may negatively impact blood sugar control and increase the risk of diabetes. Participants who used to eat fast food less often – especially those who only eat it once a month – tended to have a significantly higher likelihood of maintaining normal HbA1C levels, which suggests that reducing the frequency of fast food intake could be an important strategy for diabetes prevention or management.

Discussion

The relationship between dietary patterns and glycemic control has been a major area of focus in diabetes research. A growing body of evidence indicates that specific dietary choices, including the frequency of starch-rich food and fast food consumption, play a significant role in managing blood glucose levels and the overall glycemic control in patients with type 2 diabetes mellitus (T2DM)⁽⁵⁾. Our study at the Teaching Hospital Karapitiya, Sri Lanka, reveals that the infrequent consumption of starch-rich food (once a month) is significantly associated with normal HbA1C levels, while daily and more frequent consumption of starch-rich foods correlates with poor glycaemic control⁽⁶⁾. Similarly, infrequent consumption of fast food (once a month) was associated with better glycemic control, while those who consumed fast food more regularly experienced elevated HbA1C levels and suffered from T2DM. These findings are consistent with those from similar studies conducted in different geographical contexts.

For example, Wang et al. (2022) conducted a qualitative interview study in China to identify the relationship between dietary patterns and glycemic control in a middle-aged Chinese population⁽⁷⁾. Their study, which involved 173 participants, highlighted that a healthy dietary pattern, characterized by high consumption of whole carbohydrates, dairy, white meat, fish, fruits and vegetables, was significantly associated with reduced HbA1C levels and improved fasting plasma glucose (FPG). This aligns with our findings that healthier eating patterns, particularly those involving a lower intake of starch-rich foods and processed fast food, contribute to better glycemic control and to a lower risk of diabetes.

Further supporting the impact of diet on glycemic control, a systematic review and meta-analysis conducted by Yokoyama et al. (2022) in Japan, involving 477 patients, found that vegetarian diets led to significant reductions in HbA1C levels. This reinforces the idea that diets rich in whole plant-based foods can improve glycemic control and reduce the risk of T2DM⁽⁸⁾. Vegetarian diets, which are typically low in saturated fats and refined sugars, may improve insulin sensitivity and overall metabolic health, explaining the observed reduction in HbA1C levels.

Moreover, Atoum et al. (2023) conducted a cross-sectional study in Jordan, involving 456 female patients, to investigate the factors associated with poor glycemic control in women with T2DM⁽⁹⁾. The study revealed that 81.1% of the women had poor glycemic control, which was largely attributed to high carbohydrate and sugar consumption, and to a low intake of whole grains. These findings are consistent with those from our study, which also suggest that excessive consumption of starch-rich foods and fast food is linked to poor glycemic control.

Similarly, a cross-sectional study by Alaradi et al. (2021) in Qatar, which examined 1000 adults with T2DM, found that a fast food pattern was inversely associated with glycemic control. The study highlighted that frequent fast food consumption led to higher HbA1C levels, a finding that aligns with our study’s results⁽¹⁰⁾. We observed that participants who used to eat fast food more regularly (such as 3-4 times per week or twice a week) had elevated HbA1C levels, which is indicative of poor glycemic control and an increased risk of T2DM.

In general, these findings collectively emphasize the critical role of dietary habits in managing glycemic control. High-fiber diets, vegetarian diets and diets rich in whole carbohydrates (such as fruits, vegetables and whole grains) have been found to significantly lower HbA1C levels, thus improving diabetes management. On the other hand, fast food consumption and high intake of starch-rich foods are consistently associated with worse glycemic control and with a higher incidence of diabetes.

Our study corroborates these findings, suggesting that reducing the consumption of starch-rich foods and fast foods could be an effective dietary strategy to improve blood glucose control in individuals with T2DM. Public health initiatives encouraging healthier eating patterns, such as limiting processed food intake, could play a key role in diabetes prevention and management in both Sri Lanka and globally.

Conclusions

In summary, Figure 1 compares the frequency of starch-rich food consumption with the status of HbA1C levels in participants, showing that those who consumed starch-rich foods less frequently tended to have normal HbA1C levels, whereas those who consumed starch-rich foods more regularly were more likely to suffer from diabetes, indicating the potential impact of dietary habits on blood sugar control. The data from Figure 2 suggest a strong connection between fast food consumption and the diabetes risk: those who used to eat fast food more frequently were more likely to experience elevated HbA1C levels, indicative of poor blood sugar control or diabetes, while those who ate fast food less often tended to maintain healthier HbA1C levels. This reinforces the idea that dietary habits, particularly the consumption of highly processed foods and fast foods, play a significant role in blood sugar regulation and in the overall metabolic health.   

Corresponding author: F.M.M.T. Marikar E-mail: faiz@kdu.ac.lk

Conflict of interest: none declared.

Financial support: none declared.

This work is permanently accessible online free of charge and published under the CC-BY licence.