Weight Loss for a Healthier You Programme

The Effect of a Healthy Ketogenic Diet Versus Calorie-restricted Low Fat Diet on Weight Loss and Metabolic Outcomes for Obesity: A Randomised Controlled Trial

In view of the research gap in the safety of traditional ketogenic diet, there is a need for a healthy alternative to the ketogenic diet that reduces the individual's propensity to adverse diet choices. Healthy guidelines to be adopted include a diet low in saturated fat, trans fat, and sugar, along with adequate fibre. Potentially with these guidelines in effect, the associated risks for CVD would be reduced. Therefore, this study will investigate the effect of a calorie-restricted healthy ketogenic diet versus a calorie-restricted low fat diet on weight loss and metabolic outcomes among individuals with obesity.

Study Overview

• Status: Enrolling by invitation
• Conditions: Obesity; Metabolic Syndrome; Weight Loss; Ketogenic Dieting
• Intervention / Treatment: Other: Calorie-Restricted Healthy Ketogenic Diet; Other: Calorie-Restricted Low Fat Diet

Detailed Description

The ketogenic diet has recently gained popularity as an effective dietary plan for weight management. Some of the cited benefits include a reduction in appetite and hunger, as well as improvements in fat oxidation leading to weight loss. Remarkably, some studies have also demonstrated increases in high-density lipoprotein (HDL) cholesterol and decreases in triglyceride levels, which point to a reduction in cardiovascular disease (CVD) risk.

In spite of these, there are still widespread concerns regarding the potentially high proportion of total and saturated fats derived from ketogenic diets owing to the high-fat and moderate-protein nature. These are associated with elevated low-density lipoprotein (LDL) cholesterol levels which may offset the purportedly lower CVD risk, especially in obese individuals. Furthermore, few randomised controlled trials (RCTs) have placed emphasis on the reduction of saturated fat, leading to confounding effects on the safety of the traditional ketogenic diet. To address the research gap, our study aims to assess the effect of a calorie-restricted healthy ketogenic diet, as compared to a calorie-restricted low fat diet on weight loss and metabolic outcomes among Asian individuals with obesity.

In this randomized controlled trial, participants will be randomly assigned to either the healthy ketogenic diet (HKD) or low fat calorie-restricted diet (LFD) using computer-generated random sequencing. Both the HKD and LFD groups will attend group workshops conducted by dietitians at weeks 1, 3, 5, 7, and thereafter at 6-week intervals over the course of a 6-month period.

The participants will be recommended to achieve their incremental daily step count goal from 3,000, 7,000 to 10,000 to promote increased physical activity, as per their tolerance. All participants are to provide for their own meals and follow a calorie-restricted diet with emphasis on the consumption of healthy fats and the reduction of saturated and trans fats in both diets.

Participants in the HKD group will be advised to follow a calorie-restricted healthy ketogenic diet (n=35), with a maximum of 50g net carbohydrate intake daily. Those in the control group will be instructed to follow a calorie-restricted low fat diet (LFD) (n=35). Calorie prescriptions for both diets were calculated based on the Schofield equation, adjusted with a deficit of 500 kcal daily to promote weight loss. Participants will also be recommended to use the Nutritionist Buddy (nBuddy) mobile application to facilitate monitoring of diet intake, steps count and to aid in their adherence to the diet and physical activity recommendations.

• Study Type: Interventional
• Enrollment (Anticipated): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 119074
    • National University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Body mass index (BMI) between 27.5 to 40 kg/m2
• Aged 21 to 65 years

Exclusion Criteria:

• Individuals with type 1 diabetes or type 2 diabetes on insulin
• heart failure
• active cancer or in remission for less than 5 years
• advanced kidney disease
• hypothyroidism
• pregnancy
• depression
• untreated anemia, known thalassaemia, or other blood disorders.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Healthy Ketogenic Diet (HKD); Participants in the HKD group will be advised to follow a calorie-restricted healthy ketogenic diet (n=35), with a maximum of 50g net carbohydrate intake daily, with calorie prescriptions calculated based on the Schofield equation, adjusted with a deficit of 500 kcal daily to promote weight loss. Participants will attend group workshops conducted by dietitians at weeks 1, 3, 5, 7, and thereafter at 6-week intervals over the course of a 6-month period (total of 7 workshops). Participants will also be recommended to use the Nutritionist Buddy (nBuddy) mobile application to facilitate monitoring of diet intake, steps count and to aid in their adherence to the diet and physical activity recommendations during the 6 months period. The participants will be recommended to achieve their incremental daily step count goal from 3,000, 7,000 to 10,000 to promote increased physical activity, as per their tolerance.	Other: Calorie-Restricted Healthy Ketogenic Diet; Participants in the experimental group will be advised on a Calorie-restricted Healthy Ketogenic Diet via 7 workshops. Participants will also be advised to monitor their urinary ketones to track compliance.; Other Names: Very Low Carbohydrate Diet
ACTIVE_COMPARATOR: Low Fat caloric-restricted Diet (LFD); Participants in the reference group will be instructed to follow a calorie-restricted low fat diet (LFD) (n=35), with calorie prescriptions calculated based on the Schofield equation, adjusted with a deficit of 500 kcal daily to promote weight loss. Similar to the experimental group, participants will attend group workshops conducted by dietitians at weeks 1, 3, 5, 7, and thereafter at 6-week intervals over the course of a 6-month period (total of 7 workshops). Participants will also be recommended to use the Nutritionist Buddy (nBuddy) mobile application to facilitate monitoring of diet intake, steps count and to aid in their adherence to the diet and physical activity recommendations during the 6 months period. The participants will be recommended to achieve their incremental daily step count goal from 3,000, 7,000 to 10,000 to promote increased physical activity, as per their tolerance.	Other: Calorie-Restricted Low Fat Diet; Participants will be advised on Calorie-restricted Low Fat diet via 7 workshops.; Other Names: Weight loss diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body weight	Weight changes post intervention	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body weight	Weight changes at follow up appointments	3 months and 1 year
Blood pressure	Systolic and diastolic changes at follow up appointments	3 months, 6 months, 1 year
Hemoglobin A1c	HbA1c changes at follow up appointments	3 months, 6 months, 1 year
Fasting blood glucose	Fasting blood glucose changes at follow up appointments	3 months, 6 months, 1 year
Total cholesterol	Cholesterol changes at follow up appointments	3 months, 6 months, 1 year
Low-density lipoprotein cholesterol	Cholesterol changes at follow up appointments	3 months, 6 months, 1 year
High-density lipoprotein cholesterol	Cholesterol changes at follow up appointments	3 months, 6 months, 1 year
Triglycerides	Triglycerides changes at follow up appointments	3 months, 6 months, 1 year
Alanine transaminase	ALT changes at follow up appointments	3 months, 6 months, 1 year
Aspartate transaminase	AST changes at follow up appointments	3 months, 6 months, 1 year
Plasma 3-hydroxybutyrate (3-OHB)	Blood ketones at follow up appointments	3 months, 6 months, 1 year
Dietary intake	Nutrients intake by assessing 2-day food diaries	3 months, 6 months, 1 year
Physical activity	Physical activity frequency and intensity via self-reported questionnaire	3 months, 6 months, 1 year

Collaborators and Investigators

• Sponsor: National University Hospital, Singapore
• Investigators: Principal Investigator: Su Lin Lim, PhD, National University Hospital, Singapore

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 1, 2021
• Primary Completion (ANTICIPATED): December 31, 2022
• Study Completion (ANTICIPATED): June 1, 2023

Study Registration Dates

• First Submitted: September 9, 2021
• First Submitted That Met QC Criteria: September 9, 2021
• First Posted (ACTUAL): September 20, 2021

Study Record Updates

• Last Update Posted (ACTUAL): September 23, 2022
• Last Update Submitted That Met QC Criteria: September 21, 2022
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Keywords: Randomized controlled trial; mHealth; Low carbohydrates
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Overnutrition; Nutrition Disorders; Overweight; Insulin Resistance; Hyperinsulinism; Body Weight Changes; Obesity; Metabolic Syndrome; Weight Loss; Body Weight
• Other Study ID Numbers: 2021/00833

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will remain confidential and only accessible via lock and keys by the researchers.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No