Reporting the effectiveness of dietary intervention on weight loss outcomes in patients with obesity and overweight: a retrospective chart review at a Center of Excellence in UAE

Abstract

Background

A modest weight loss of ≥5 % among patients with obesity is associated with a reduced risk of type 2 diabetes, hypertension, and other obesity-related complications. Dietary interventions play a central role in obesity management and improving metabolic health, yet region-specific data from the United Arab Emirates (UAE) remains limited.

Methods

This retrospective chart review aims to assess effectiveness of dietary intervention on weight loss outcomes in patients with overweight and obesity attending a Center of Excellence for Weight Reduction and Obesity Management in UAE. This study included adult patients with BMI ≥25 kg/m² who received individualized dietary counseling between September 2018 and September 2021. Patients who had undergone bariatric procedures or on obesity medications were excluded. Anthropometric and body composition data were collected before and after intervention. Outcomes included changes in weight, BMI, fat mass, visceral fat, and other metabolic parameters. Statistical analyses included paired t-tests, correlation coefficients, and multivariate regression to assess associations between intervention frequency, duration, and weight-related outcomes.

Results

A total of 266 patients (mean age 44.46 ± 8.18 years; 63.9 % female) were included. Following the intervention, participants achieved significant mean weight loss of 5.12 % (p < 0.001), with corresponding reductions in BMI (4.93 %, p < 0.001), fat mass (10.11 %, p < 0.001), and visceral fat (34.34 %, p = 0.014). More frequent sessions and longer follow-up durations were significantly associated with greater improvements in BMI, fat mass, and fat percentage. Gender-based analysis revealed that males experienced greater reductions in fat mass and resting energy expenditure compared to females.

Conclusion

The dietary intervention resulted in significant improvements in anthropometric and body composition indices. These findings support the efficacy of individualized, dietitian-led interventions in managing obesity. The observed gender differences highlight the importance of tailored approaches in obesity care. This study contributes to the limited body of evidence on effective, non-pharmacological obesity management strategies in UAE.

Graphical abstract

Abbreviations

BMI

Body Mass Index

HIS

Health Information System

GCP

Good Clinical Practice

SD

Standard Deviation

SECA

Medical body composition analyzer brand used in anthropometric measurements

URN

Unique Record Number

SPSS

Statistical Package for the Social Sciences

T2DM

Type 2 Diabetes Mellitus

OSA

Obstructive Sleep Apnea

MASLD

Metabolic Dysfunction-Associated Steatotic Liver Disease

MASH

Metabolic Dysfunction-Associated Steatohepatitis

1. Introduction

Obesity is a chronic, multifactorial disease that has reached epidemic proportions globally. According to the World Health Organization (WHO), an estimated 2.5 billion adults were overweight in 2022, including more than 890 million adults with obesity (Body Mass Index ≥30 kg/m²) [1]. This corresponds to 43 % of the global adult population having overweight and 16 % having obesity [1]. The burden is particularly significant in the Middle East, as shown by recent data from the Global Obesity Observatory, which shows that in the United Arab Emirates (UAE), 25.1 % of men and 30.6 % of women have obesity [2]. Furthermore, another study in the UAE showed that the highest rate of obesity was amongst UAE nationals with a prevalence of 39.6 % [3]. These figures are expected to rise, with the World Obesity Federation estimating that the number of adults living with obesity will surpass one billion globally by 2030 [4].

The health, economic, and social implications of obesity are substantial. Obesity increases the risk of a range of chronic diseases, including type 2 diabetes mellitus (T2DM), cardiovascular disease, metabolic dysfunction-associated steatotic liver disease (MASLD), obstructive sleep apnea (OSA), certain malignancies, and osteoarthritis [5,6]. In addition to the physical burden, obesity negatively affects mental health through stigma, reduced self-esteem, and increased incidence of depression. Functional limitations, such as impaired mobility and physical activity, further reduce quality of life and workforce productivity, leading to absenteeism and early retirement [7]. The complex interplay between physical, psychological, and social dimensions makes obesity a particularly challenging condition to address in both clinical and public health contexts.

Treatment approaches for obesity encompass lifestyle interventions, medications, and bariatric surgery. Dietary modification and physical activity remain the cornerstones of treatment, with behavioral interventions playing a critical role in sustaining these changes [8]. Pharmacologic agents approved for obesity management include bupropion-naltrexone, orlistat, phentermine-topiramate, and GLP-1 receptor agonists such as tirzepatide and semaglutide, which have shown significant weight-reduction benefits in randomized controlled trials and real-world studies [9,10]. For patients with severe obesity (BMI ≥35 kg/m²), bariatric surgery is an effective intervention that leads to sustained weight loss and remission of comorbid conditions. According to the American Society for Metabolic and Bariatric Surgery (ASMBS), patients with BMI ≥30 kg/m² with significant comorbidities may also be considered for surgical or endoscopic intervention [11].

Despite the strong evidence supporting lifestyle and dietary interventions, there remains a lack of region-specific data on the effectiveness of dietitian-led obesity treatment in the UAE. Therefore, the aim of this study is to evaluate the impact of dietary interventions on weight loss outcomes in patients with overweight or obesity attending a weight management centre in Dubai. Additionally, the study investigates whether the frequency and duration of sessions with a registered dietitian are associated with clinically significant reductions in body weight and adiposity measures.

2. Material & methods

2.1. Study design and setting

This retrospective chart review evaluated the effectiveness of a dietary intervention on weight loss outcomes in patients with overweight and obesity attending a Center of Excellence for Weight Reduction and Obesity Management in the United Arab Emirates (UAE). The study included patients who received individualized dietary counseling between September 2018 and September 2021. The counseling sessions focused on weight loss, teaching the caloric deficit model with macronutrient distributions, and providing personalized nutrition advice, goal setting, and behavior modification strategies to support sustainable lifestyle changes. The primary aim was to evaluate the association between weight loss outcomes and both the frequency and cumulative duration of dietitian-led interventions. This study was conducted and reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines for observational research [12].

2.2. Study population

Patients were eligible for inclusion if they were aged 18 years or older and had a baseline body mass index (BMI) of ≥25 kg/m². Only patients who received dietary intervention alone, without the use of obesity medications or bariatric procedures, were included. Patients were excluded if they had undergone endoscopic or surgical weight loss procedures (e.g., sleeve gastrectomy or intragastric balloon) or if they were on obesity medications.

2.3. Sample size and sampling technique

A total of 388 eligible patients were identified using convenience sampling. The participant selection process is summarized in Fig. 1. Of the 388 patients assessed for enrolment, 115 were excluded before screening due to prior bariatric procedures or the use of obesity medications. Of the 273 patients screened, 7 were excluded as outliers (e.g., pregnancy). A total of 266 participants met the inclusion criteria and had complete follow-up and anthropometric data available during the study period, and hence, were included in the final analysis.

Fig. 1.

STROBE flow chart illustrating patient selection and exclusions.

2.4. Data sources and variables

Data were extracted from the electronic Health Information System (HIS) and SECA body composition analysis reports. Each patient's unique record number (URN) was used to confirm participation in the dietary program, and eligibility was verified through review of dietetic consultation notes and patient history. The following variables were collected at baseline and follow-up: age, gender, ethnicity, smoking status, physical activity level, weight (kg), height (cm), BMI (kg/m²), fat mass (kg and %), muscle mass (kg), waist circumference (cm), visceral fat (L), resting energy expenditure (kcal), and phase angle (°). Exposure variables included the number of dietitian sessions (frequency), total follow-up duration in months (dose), and average time between sessions (months).

2.5. Data collection procedures

All measurements were conducted by trained staff following standardized SECA protocols. Data collection was carried out by investigators trained in Good Clinical Practice (GCP), and accuracy was ensured through cross-verification by two independent reviewers. All patient identifiers were anonymized, and data were stored on a secure, password-protected institutional server in compliance with local data protection regulations.

2.6. Outcomes

The primary outcomes were total weight loss (kg) and percentage change from baseline, and their association with both the number and total length of treatment (months) of dietetic sessions. Secondary outcomes included changes in BMI, fat mass, waist circumference, visceral fat, and muscle mass.

2.7. Intervention protocol

All patients underwent a comprehensive nutritional assessment based on the ABCD model, incorporating Anthropometric, Biochemical, Clinical, and Dietary evaluations.

Anthropometric measurements included body weight, BMI, waist and hip circumference, and a full body composition analysis assessing fat mass, skeletal muscle mass, hydration status, visceral fat, resting energy expenditure, and total energy expenditure, using standardized SECA body composition analyzers. Available laboratory data were reviewed to evaluate metabolic and nutritional status.

Biochemical (laboratory) assessment focused on key parameters relevant to obesity and metabolic health, including fasting blood glucose, HbA1c, lipid profile (total cholesterol, LDL-C, HDL-C, triglycerides), liver function tests (ALT, AST), renal function tests (creatinine, urea), thyroid function tests (TSH, free T4), vitamin D levels, iron status (ferritin, transferrin saturation), and markers of inflammation such as C-reactive protein (CRP). Additional micronutrient markers, including vitamin B12, folate, and magnesium, were reviewed when clinically indicated.

Clinical assessment encompassed a detailed medical history, current medications, supplement use, sleep patterns, digestive health, physical activity habits, social context (e.g., living situation and work demands), as well as the presence of any pressure ulcers, vomiting, diarrhea, or other relevant symptoms.

Dietary assessment involved analyzing habitual eating patterns, meal frequency and timing, reliance on dining out, a 24-h dietary recall, food frequency questionnaire, and fluid intake (including water, coffee, sugary beverages, and alcohol). Emotional or disordered eating behaviors were also evaluated. Based on these evaluations, the dietitian estimated each patient's habitual energy intake and developed a personalized meal plan, typically creating an energy deficit of approximately 500 kcal/day, adjusted according to individual clinical needs and goals.

The dietary intervention was tailored to achieve a gradual weight loss of 0.5–1 kg per week, consistent with international guidelines. Macronutrient distribution was generally set at approximately 45–50 % carbohydrates (favoring whole grains and fiber-rich sources), 20–25 % protein (emphasizing lean meats, fish, legumes, and low-fat dairy), and 25–30 % fats (prioritizing unsaturated fats such as olive oil, nuts, and seeds).

Patients were educated using practical tools, including the MyPlate method and culturally adapted portion visuals. Behavior change techniques included goal setting and self-monitoring (e.g., food diaries, body composition tracking) to enhance adherence. Education covered topics such as mindful eating, strategies to reduce emotional eating, meal preparation skills, and healthier choices when dining out. Motivational interviewing techniques were used by the dietitian to enhance engagement and adherence.

Follow-up sessions focused on monitoring progress, addressing barriers, and making individualized adjustments to meal plans and behavioral strategies. The overall approach emphasized a patient-centered, flexible, and realistic dietary pattern aimed at supporting long-term weight management and metabolic health.

2.8. Statistical analysis

Statistical analysis was conducted using IBM SPSS Statistics version 29.0 (IBM Corp., Armonk, NY, USA; released 2024). Descriptive statistics were used to summarize baseline demographic and clinical characteristics. Continuous variables were reported as means and standard deviations (SD), while categorical variables were presented as frequencies and percentages. Paired t-tests were used to compare pre- and post-intervention anthropometric measures. Correlation analyses (Pearson or Spearman, based on normality testing) were used to examine the relationship between weight loss and session frequency and duration. Multivariate linear regression models were developed to adjust for potential confounders, including age, gender, and baseline BMI. Subgroup analyses were conducted among patients with BMI ≥40 kg/m² and by sex to explore differences in weight loss outcomes. A p-value of <0.05 was considered statistically significant.

3. Results

A total of 266 participants were included in this study, with a mean age of 44.46 ± 8.18 years. The majority were female (63.9 %) and of Caucasian ethnicity (80.8 %). A sedentary lifestyle was reported by 53 % of participants, while 20.3 % engaged in light activity, 20.3 % in moderate activity, and 5.3 % in extreme activity. The average length of treatment was 6.15 ± 7.92 months, with a mean total number of sessions being 4.47 ± 3.38 (Table 1).

Table 1.

Description of the sample characteristics (n = 266).

Variable	Minimum – Maximum	Mean ± S.D.
Age (years)	23.0–69.0	44.46 ± 8.18
Total number of sessions	2.0–23.0	4.47 ± 3.38
Length of treatment (months)	1.0–48.0	6.15 ± 7.92

Variable		Frequency N	Percent %
Sex	Females	170	63.9
	Males	96	36.1
Ethnicity	Caucasian	215	80.8
	Asian	36	13.5
	American	6	2.3
	African	9	3.4
Smoking	Yes	34	12.8
	No	208	78.2
	Ex-smoking	24	9.0
Physical Activity	Sedentary (less than 1 h weekly)	141	53.0
	Light Active (1–3 days a week)	54	20.3
	Moderate Active (4–5 days a week)	54	20.3
	Extremely Active (6–7 days a week)	14	5.3
	Not Reported	3	1.1

Following the dietary intervention, significant reductions were observed in weight (5.12 %), from 90.51 ± 20.02 kg to 85.88 ± 19.77 kg (p < 0.001), and BMI (4.93 %) from 31.82 ± 5.95 kg/m² to 30.25 ± 5.64 kg/m² (p < 0.001). Fat mass decreased significantly (10.11 %) from 36.98 ± 13.35 kg to 33.24 ± 12.34 kg (p < 0.001), while fat percentage dropped 2.06 %, from 40.05 ± 7.37 % to 37.99 ± 8.16 % (p < 0.001), highlighting improvements in body composition. Waist circumference significantly decreased (7.25 %) from 99.89 ± 18.76 cm to 92.65 ± 21.09 cm (p < 0.001), while visceral fat dropped (34.34 %) from 3.99 ± 3.56 L to 2.62 ± 2.01 L (p = 0.014). Muscle mass exhibited a slight decline (6.41 %), from 27.13 ± 17.40 kg to 25.39 ± 7.42 kg (p = 0.063), but this change was not statistically significant, indicating muscle preservation during weight loss. Resting energy expenditure (REE) decreased 3.27 %, from 1733.13 ± 320.60 kcal to 1676.41 ± 292.33 kcal (p < 0.001), but phase angle remained unchanged at 5.44 ± 0.66° (p = 0.904) (Table 2).

Table 2.

Comparison between anthropometric indices before and after treatment (n = 266).

Variable	Pre-Treatment	Post-Treatment	Percentage Change (%)	p-value
Weight (kg)	90.51 ± 20.02	85.88 ± 19.77	5.12	<0.001
BMI (kg/m2)	31.82 ± 5.95	30.25 ± 5.64	4.93	<0.001
Fat (kg)	36.98 ± 13.35	33.24 ± 12.34	10.11	<0.001
Fat (%)	40.05 ± 7.37	37.99 ± 8.16	2.06	<0.001
Muscle Mass (kg)	27.13 ± 17.40	25.39 ± 7.42	6.41	0.063
Waist Circumference (cm)	99.89 ± 18.76	92.65 ± 21.09	7.25	<0.001
Visceral Fat (L)	3.99 ± 3.56	2.62 ± 2.01	34.34	0.014
REE (kcal)	1733.13 ± 320.60	1676.41 ± 292.33	3.27	<0.001
Phase Angle (°)	5.44 ± 0.66	5.44 ± 0.66	0.00	0.904

Paired sample t-test.

Correlation analysis revealed significant positive correlations between the total number of dietetic sessions and reductions in BMI (r = 0.220, p < 0.001), fat mass (r = 0.195, p = 0.001), and fat percentage (r = 0.121, p = 0.048), indicating that more sessions were associated with greater improvements in body composition. Additionally, visceral fat was positively correlated with cessation periods (r = 0.156, p = 0.011), suggesting that longer interruptions in follow-up were linked to less favorable outcomes. The cessation period was defined as a break in follow-up with the dietitian, highlighting the importance of regular follow-ups – or shorter gaps – for sustained improvements in visceral fat levels (Table 3). Interestingly, however, some patients continued to lose weight despite cessation periods exceeding three months. While the exact reasons for this are unclear, it is possible that sustained lifestyle changes or other individual factors may have contributed to their continued progress.

Table 3.

Correlation between the change in anthropometric indices and the number of treatment sessions (n = 266).

Variable	Change results by the treatment (= initial - final) (mean)		Total sessions	Length treatment in months	Cessation period of more than 3 months
Weight (kg)	4.63 ± 8.12	Correlation	0.112	0.024	−0.235
		p-value	0.067	0.698	<0.001
BMI (kg/m2)	1.57 ± 1.95	Correlation	0.220	0.064	−0.248
		p-value	<0.001	0.297	<0.001
Fat (kg)	3.74 ± 5.15	Correlation	0.195	0.149	0.132
		p-value	0.001	0.015	0.031
Fat (%)	2.05 ± 3.33	Correlation	0.121	0.123	0.023
		p-value	0.048	0.046	0.706
Muscle Mass (kg)	1.74 ± 15.23	Correlation	−0.010	−0.012	0.015
		p-value	0.873	0.844	0.811
Waist Circumference (cm)	7.24 ± 14.33	Correlation	0.065	0.073	0.005
		p-value	0.294	0.234	0.932
Visceral Fat (L)	1.37 ± 9.06	Correlation	−0.030	−0.025	0.156
		p-value	0.628	0.686	0.011
REE (kcal)	56.71 ± 71.67	Correlation	−0.218	0.141	0.179
		p-value	<0.001	0.021	0.003
Phase Angle (°)	0.0023 ± 0.31	Correlation	0.058	−0.041	0.064
		p-value	0.346	0.505	0.300

Correlation t-test.

Gender-based analysis showed that males exhibited significantly greater reductions in fat mass (5.15 ± 6.52 kg vs. 2.95 ± 3.99 kg, p < 0.001), fat percentage (3.09 ± 3.67 % vs. 1.46 ± 2.97 %, p < 0.001), and REE (87.11 ± 97.50 kcal vs. 39.55 ± 43.46 kcal, p < 0.001) compared to females. However, differences in weight loss (p = 0.075), BMI reduction (p = 0.102), muscle mass change (p = 0.059), and waist circumference (p = 0.068) between males and females were not statistically significant (Table 4).

Table 4.

Comparison of the change in anthropometric indices between males and females (n = 266).

Variable	Females (n = 170)	Males (n = 96)	p-value
Weight (kg)	4.13 ± 8.94	5.50 ± 6.39	0.075
BMI (kg/m2)	1.46 ± 1.90	1.78 ± 2.04	0.102
Fat (kg)	2.95 ± 3.99	5.15 ± 6.52	<0.001
Fat (%)	1.46 ± 2.97	3.09 ± 3.67	<0.001
Muscle Mass (kg)	0.64 ± 1.85	3.68 ± 25.20	0.059
Waist Circumference (cm)	6.25 ± 12.98	8.98 ± 16.38	0.068
Visceral Fat (L)	1.26 ± 11.08	1.57 ± 3.27	0.397
REE (kcal)	39.55 ± 43.46	87.11 ± 97.50	<0.001
Phase Angle (°)	−0.03 ± 0.29	0.06 ± 0.32	0.030

Independent sample t-test.

4. Discussion

This study demonstrates the effectiveness of dietary intervention in achieving meaningful weight loss and improvements in body composition among patients with overweight and obesity. A mean weight reduction of over 5 % aligns with clinical thresholds known to reduce the risk of developing type 2 diabetes, hypertension, and other metabolic conditions [13]. These findings are in line with previous research, which emphasizes that while the specific type of diet may vary, creating and sustaining an energy deficit is the most important factor in achieving weight loss [14].

The reductions in fat mass, fat percentage, and especially visceral fat suggest that the intervention had a positive impact not only on general weight but also on central adiposity, which is more strongly linked to cardiometabolic risk [15]. Visceral fat has been associated with insulin resistance, dyslipidemia, and inflammation, and its reduction is a key target in obesity management. This is supported by evidence from the DiRECT trial [16], which showed that structured dietary interventions can lead to significant weight loss and even remission of type 2 diabetes, particularly in those with higher baseline risk.

The correlation between the number of dietetic sessions and improvements in BMI, fat mass, and fat percentage highlights the importance of regular follow-up. More frequent sessions were associated with better outcomes, which supports existing literature advocating for sustained engagement in lifestyle modification programs [17]. On the other hand, the positive association between longer cessation periods and visceral fat levels suggests that breaks in care may lead to a reversal of progress, further reinforcing the need for consistent follow-up.

Muscle mass decreased slightly during the intervention, but this change was not statistically significant, indicating that lean body mass was largely preserved. This is an important consideration, as maintaining muscle mass helps support metabolic rate and functional status, particularly in longer-term weight management. While resting energy expenditure (REE) did decrease, this is expected with weight loss and has been well-documented as a physiological adaptation to lower body mass. Studies suggest that reductions in REE are proportional to fat mass loss and are not necessarily detrimental, especially when muscle preservation is achieved [18,19].

Gender differences observed in fat loss and REE changes suggest that males may respond more robustly to dietary interventions, particularly in terms of fat reduction and metabolic adaptation [20]. This could be attributed to differences in body composition, hormonal influences, and baseline metabolic rates. However, since weight and BMI reductions were not significantly different between genders, the data still support the overall benefit of dietary interventions for both males and females, emphasizing the value of individualized approaches rather than gender-specific strategies.

These findings also align with broader research on dietary patterns and cardiometabolic outcomes. For instance, adherence to the Mediterranean diet has been associated with a lower incidence of cardiovascular events, improved lipid profiles, and reduced inflammation, reinforcing the idea that diet quality is as important as quantity in long-term risk reduction [21]. Additionally, evidence from digital and hybrid models of care, such as internet-based lifestyle programs, supports the effectiveness of remote interventions in improving lipid levels and promoting adherence [22].

Finally, integrating dietary changes with physical activity may further enhance outcomes. Findings from a post-hoc analysis of the Look AHEAD trial demonstrated that individuals who achieved ≥7 % weight loss combined with higher levels of physical activity had significantly lower cardiovascular event rates [23]. Although physical activity was not the focus of this study, these findings suggest that future programs could benefit from incorporating exercise counseling to optimize metabolic improvements.

5. Limitations

Although SECA bioimpedance devices provide practical and reproducible estimates of body composition, they are indirect measurement tools. Their accuracy in quantifying visceral adipose tissue is limited compared with gold-standard imaging such as MRI or CT. Similarly, resting energy expenditure (REE) derived from bioimpedance equations is less accurate than indirect calorimetry and should be interpreted as an estimate rather than a metabolic measurement. These methodological constraints may partly explain variability in visceral fat and REE changes observed in our cohort.

Additionally, although the UAE's national population is not predominantly Caucasian, it is diverse, and this clinic's catchment area and referral patterns resulted in a predominantly expatriate and Caucasian patient population. While this does not represent the demographic distribution of the UAE as a whole, it accurately reflects the subset of individuals who seek care at this specialized center and therefore remains relevant to understanding outcomes in this segment of the population.

6. Conclusion

This retrospective chart review highlights the significant impact of structured dietary interventions on weight loss outcomes among patients with overweight and obesity in a specialized center in the UAE. The findings demonstrate that sustained engagement with nutrition services, longer follow-up duration, and reduced interruptions in care are associated with greater weight loss and higher achievement of clinically significant outcomes. These results underscore the importance of individualized dietary counseling and continuity of care in managing obesity. Further prospective studies are warranted to validate these findings and explore long-term outcomes in diverse populations across the UAE.

Clinical takeaways

• •Individualized, dietitian-led interventions resulted in clinically meaningful weight loss and improvements in fat mass and visceral fat.
• •Greater session frequency and uninterrupted follow-up were associated with superior outcomes.
• •Structured dietary counseling is an effective non-pharmacologic therapy and should be integrated into comprehensive obesity management programs in the UAE.

Author contribution

M.J. contributed to the conceptualization, data collection, and drafting of the manuscript. M.K. was involved in data analysis, manuscript writing, and supervision. M.M. contributed to data analysis, writing and reviewing the manuscript drafts. F.A. participated in writing and reviewing manuscript drafts. D.A. provided statistical analysis support. S.G. contributed to the study's conceptualization and supervised the project.

Ethics/institutional review board aproval

This study was reviewed and approved by the Mediclinic Middle East Institutional Review Board (Dubai, UAE). Informed consent was waived due to the retrospective design.

Disclosures

All authors report no relationships that could be considered conflicts of interest. All authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.

Declaration of use of artificial intelligence

Artificial intelligence was used to support language refinement and formatting during manuscript revision. No AI tool was used for data analysis, interpretation, or generation of scientific content.

Funding statement

This research received no external funding.