Effect of Low-calorie Diets With Different Macronutrient... | NCT06912555

Status Module

Name	Class
Hospital Miguel Servet	OTHER

Description Module

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
A. Low-calorie and high-protein diet with high-protein dinner (60% of total daily protein)	Experimental	The macronutrient distribution will be initially based on a protein intake of 1.3-1.5 g/kg of body weight. From this protein intake, the total calorie intake will be calculated, and 30% of these calories will be allocated to fat consumption. The remaining calories will be allocated to carbohydrate consumption, depending on the amount of protein consumed. The protein will be distributed as follows: breakfast and lunch (~40%), and dinner (~60%). The caloric restriction will be moderate, involving a reduction of 30% of the total energy expenditure, specifically calculated for each individual. This reduction will result in approximately 400-600 kcal decrease per day compared to the participant's usual energy needs. It is important to note that the caloric content of the diet will never be less than 1200 kcal per day, as such a diet may not meet the participant's nutritional requirements.	Other: Diet
B. Low-calorie and high-protein diet with low-protein dinner (15% of total daily protein)	Experimental	The macronutrient distribution will be initially based on a protein intake of 1.3-1.5 g/kg of body weight. From this protein intake, the total calorie intake will be calculated, and 30% of these calories will be allocated to fat consumption. The remaining calories will be allocated to carbohydrate consumption, depending on the amount of protein consumed.The protein will be distributed as follows: breakfast and lunch (~85%), and dinner (~15%). The caloric restriction will be moderate, involving a reduction of 30% of the total energy expenditure, specifically calculated for each individual. This reduction will result in approximately 400-600 kcal decrease per day compared to the participant's usual energy needs. It is important to note that the caloric content of the diet will never be less than 1200 kcal per day, as such a diet may not meet the participant's nutritional requirements.	Other: Diet
C. Low-calorie and regular-protein diet

Interventions

Name	Type	Description	Arm Group Labels	Other Names
Diet	Other	The nutritional plan will be initially based on a protein intake of 1.3 to 1.5 g per kilogram of body weight. From this, the total daily calorie intake is calculated, with 30% of the calories allocated to fats. The remaining calories will be assigned to carbohydrates, depending on the protein intake. Protein distribution will be approximately 40% at breakfast and lunch, and 60% at dinner. Caloric restriction will be moderate, reducing the total energy expenditure by 30%-calculated individually-which translates to an approximate decrease of 400 to 600 kcal per day compared to the participant's usual energy needs. It is important to note that the diet will never provide less than 1200 kcal per day to ensure that the minimum nutritional requirements are met.

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Glucose change.	Glucose change assessed by difference in fasting glucose concentration (mg/dL and %) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
Glycated hemoglobin change.	Glycated change assessed by difference in glycated hemoglobin concentration (%) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
Insulin change.	Insulin change assessed by difference in fasting insulin concentration (UI/mL and %) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
HOMA-IR change.	HOMA-IR change assessed by difference in HOMA-IR concentration (absolute units and %) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
Body fat mass change.	Body fat mass change assessed by difference in fat mass (%) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
Fat-free mass change.	Fat-free mass change assessed by difference in fat free-mass (%) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
Visceral fat mass change.	Visceral fat mass change assessed by difference in visceral fat mass (kg and %) comparing 3 months visit with respect to baseline.

Secondary Outcomes

Measure	Description	Time Frame
Total cholesterol change.	Total cholesterol change assessed by difference in fasting total cholesterol concentration (mg/dL and %) comparing 3 months visit with respect to baseline.	After 3 months of intervention.
LDL cholesterol change.

Eligibility Module

Eligibility Criteria

Inclusion Criteria:

Body mass index (BMI) ranging between 27.5 and 40 kg/m2.
Presence of prediabetes (fasting glucose between 100-125 mg/dL and/or glycated hemoglobin between 5.7 and 6.4%) or type 2 diabetes mellitus (fasting glucose ≥ 126 mg/dL and/or glycated hemoglobin ≥ 6.5% and/or currently taking metformin), based on the criteria of the American Diabetes Association.
Engaged in shift work, including night shifts, for at least 1 year and intending to maintain this schedule in the upcoming months.
Provide written informed consent for voluntary participation in the study after reviewing the participant information sheet and addressing any resulting queries.

Exclusion Criteria:

Treatment with antidiabetic medications (oral or subcutaneous) or insulin in the last 2 months, except for stable use of metformin or Dipeptidyl peptidase 4 (DPP-4) inhibitors for a minimum of 6 months.
Treatment with lipid-lowering agents in an unstable manner for at least 6 months prior to study entry.
Regular consumption of functional foods such as phytosterols or red yeast rice, which have a significant effect on lipid or glucose metabolism, in an unstable manner for at least 6 months prior to study entry.
Presence of other chronic conditions that are not well-controlled and could interfere with study outcomes, such as cardiovascular disease, renal disease, or liver disease.
Presence of uncontrolled endocrine disorders, including hypothyroidism.
Use of medications that could interfere with lipid and/or glucose metabolism, unless taken stably throughout the study.
Consumption of sleep supplements, except for stable use for 6 months with the intention to continue stable use throughout the study.
Presence of any laboratory abnormalities that could affect study results.
Weight gain or loss of ≥ 5% in the last 3 months.
Use of vitamin supplements in an unstable manner for at least 6 months prior to study entry.
High intake of alcohol (> 30 g of ethanol) on a regular basis.
Pregnancy or intention to become pregnant during the study.
Severe illness of any kind with a life expectancy of less than 1 year or that, in the investigators' judgment, limits uniform dietary intake throughout the study.
Any other circumstance that, in the investigators' judgment, would impede adequate adherence to the proposed nutritional intervention (e.g., frequent travel during the study, inability to attend visits due to personal or work-related circumstances, etc.).

ID	Term
D003924	Diabetes Mellitus, Type 2
D050177	Overweight
D009765	Obesity
D011236	Prediabetic State

ID	Term
D003920	Diabetes Mellitus
D044882	Glucose Metabolism Disorders
D008659	Metabolic Diseases
D009750	Nutritional and Metabolic Diseases
D004700	Endocrine System Diseases
D044343	Overnutrition
D009748	Nutrition Disorders
D001835	Body Weight
D012816	Signs and Symptoms
D013568	Pathological Conditions, Signs and Symptoms

ID	Term
D009747	Nutritional Physiological Phenomena
D000066888	Diet, Food, and Nutrition
D010829	Physiological Phenomena