Healthy Volunteers, Postprandial Metabolism
Conditions
Keywords
Diet-Induced Thermogenesis, Respiratory Quotient, Indirect Calorimetry, Substrate Oxidation, Sustainable Diet, Hydration Status, Satiety, Healthy Young Men
Brief summary
This randomized crossover study evaluated the acute postprandial metabolic and hydration responses to two standardized lunch meals differing in nutritional quality and environmental footprint in healthy young men. Each participant consumed both meals in separate experimental visits according to a randomized sequence. Postprandial oxygen consumption, carbon dioxide production, respiratory quotient, energy expenditure, diet-induced thermogenesis, substrate oxidation, satiety, and hydration-related outcomes were assessed.
Detailed description
The THERMOS-LUNCH study (Thermogenesis, Hydration, Environmental Impact, Respiratory Quotient, Meals, Substrate Oxidation and Sustainability after Lunch in University Students: a Nutritional Crossover Study in Healthy Subjects) was a randomised, two-period, two-sequence crossover intervention study conducted in healthy male university students. The study compared two standardised lunch meals that differed in nutritional quality and estimated environmental impact: a healthy and sustainable meal and a less healthy and non-sustainable comparison meal. Participants were randomly assigned to one of two intervention sequences: the healthy and sustainable meal followed by the comparison meal, or the comparison meal followed by the healthy and sustainable meal. The two experimental visits were separated by a 7-day washout period. During each experimental visit, postprandial metabolic responses were assessed using portable indirect calorimetry. Oxygen consumption, carbon dioxide production, respiratory exchange ratio, energy expenditure, diet-induced thermogenesis and substrate oxidation were measured during the fasting baseline period and over the 4-hour postprandial period. Subjective appetite and satiety sensations were assessed repeatedly using 100-millimetre visual analogue scales. Hydration-related measures included total fluid intake, urine volume, urine colour and urine specific gravity measured using a digital refractometer. Total urinary nitrogen, obtained from the 24-hour urine collection, was used to account for protein metabolism in substrate-oxidation calculations, while urinary creatinine was used as a quality-control marker for the plausibility and completeness of the 24-hour urine collection.
Interventions
OTHERHealthy-Sustainable Test Meal
Standardized lunch meal characterized by a healthier nutritional profile and lower environmental footprint. The meal was designed to have lower carbon and water footprints compared with the non-sustainable test meal. The healthy-sustainable meal had an estimated carbon footprint of 620 g CO₂-eq and water footprint of 956.6 L, whereas the non-sustainable meal had an estimated carbon footprint of 1104 g CO₂-eq and water footprint of 1605.1 L.
OTHERNon-Sustainable Test Meal
Standardized lunch meal characterized by a less favorable nutritional profile and higher environmental footprint compared with the healthy-sustainable test meal. The healthy-sustainable meal had an estimated carbon footprint of 620 g CO₂-eq and water footprint of 956.6 L, whereas the non-sustainable meal had an estimated carbon footprint of 1104 g CO₂-eq and water footprint of 1605.1 L.
Sponsors
University of Parma
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Participants completed two experimental visits in a randomized two-period, two-sequence crossover design. Each participant received both test meals, one healthy-sustainable and one non-sustainable, in separate visits separated by a 7-day washout period. In one sequence, participants received the healthy-sustainable meal at T0 and the non-sustainable meal at T1; in the opposite sequence, participants received the non-sustainable meal at T0 and the healthy-sustainable meal at T1.
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Male participants aged 18 to 30 years. * Students enrolled at the University of Parma. * Residence or domicile in areas surrounding the University of Parma campus. * Stable body weight during the previous 6 months, defined as body weight change within ±5%. * Good general health. * Willingness to comply with study procedures. * Written informed consent provided before participation.
Exclusion criteria
* Female sex. * Age younger than 18 years or older than 30 years. * Smoking. * Food allergies or food intolerances incompatible with the test meals. * Chronic noncommunicable food-related diseases, including metabolic, endocrine, or chronic disorders. * Residence or domicile outside areas adjacent to the University of Parma campus. * Students enrolled at the University of Parma in Gastronomic Sciences or Human Nutrition Sciences.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diet-Induced Thermogenesis | Baseline and 0-240 minutes after test meal consumption during each experimental visit | Diet-induced thermogenesis will be calculated from postprandial energy expenditure measured by portable indirect calorimetry after consumption of each test meal. |
| Respiratory Quotient | Baseline and 0-240 minutes after test meal consumption during each experimental visit | Respiratory quotient will be calculated from oxygen consumption and carbon dioxide production measured by portable indirect calorimetry at fasting baseline and during the postprandial period. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Repeated Hunger Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Description: Hunger was assessed using a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "I am not hungry at all", to 100 millimetres, anchored by "I have never been so hungry". Higher scores indicate greater hunger and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Satiety Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Satiety was assessed using the question "How satisfied do you feel?" on a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "I feel completely empty", to 100 millimetres, anchored by "I cannot eat even a single bite". Higher scores indicate greater satiety and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Fullness Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Fullness was assessed using a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "Not at all full", to 100 millimetres, anchored by "Completely full". Higher scores indicate greater fullness and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Prospective Food Consumption Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | spective food consumption was assessed using the question "How much do you think you could eat?" on a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "Nothing", to 100 millimetres, anchored by "A lot". Higher scores indicate greater prospective food consumption and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Desire for Sweet Food Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Desire for sweet food was assessed using the question "Would you like to eat something sweet?" on a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "None", to 100 millimetres, anchored by "A lot". Higher scores indicate a greater desire to eat sweet food and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Desire for Salty Food Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Desire for salty food was assessed using the question "Would you like to eat something salty?" on a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "Yes, very much", to 100 millimetres, anchored by "No, not at all". Higher scores indicate a lower desire to eat salty food and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Desire for Savoury Food Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Desire for savoury food was assessed using the question "Would you like to eat something savoury?" on a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "Yes, very much", to 100 millimetres, anchored by "No, not at all". Higher scores indicate a lower desire to eat savoury food and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Repeated Desire for Fatty Food Scores Assessed Using a 100-Millimetre Visual Analogue Scale | From the fasting assessment before the standardised breakfast to 240 minutes after consumption of the test lunch, during each experimental visit. | Desire for fatty food was assessed using the question "Would you like to eat something fatty?" on a 100-millimetre visual analogue scale ranging from 0 millimetres, anchored by "Yes, very much", to 100 millimetres, anchored by "No, not at all". Higher scores indicate a lower desire to eat fatty food and do not necessarily represent a better or worse outcome. Scores were recorded repeatedly at the scheduled assessment time points during each experimental visit and are reported in millimetres. |
| Total Fluid Intake | Over the 24-hour study period associated with each experimental condition. | Total fluid intake was calculated as the sum of all measured fluids consumed during each experimental condition. One total value was calculated for each participant under each experimental condition and is expressed in millilitres. |
| Total 24-Hour Urine Volume | Over the 24-hour urine-collection period associated with each experimental condition. | All urine produced during each 24-hour collection period was collected, and the total urine volume was measured. One total value was calculated for each participant under each experimental condition and is expressed in millilitres per 24 hours |
| Morning Spot Urine Specific Gravity | At the fasting morning urine collection before breakfast during each experimental visit. | Urine specific gravity was measured in the morning spot urine sample using a digital refractometer. Triplicate measurements were averaged to obtain one value for each participant at each experimental visit. Urine specific gravity is dimensionless, and higher values indicate more concentrated urine. |
| Urine Specific Gravity of the Pooled 24-Hour Urine Collection | At completion of the 24-hour urine-collection period associated with each experimental condition. | Urine specific gravity was measured in the pooled 24-hour urine sample using a digital refractometer. Triplicate measurements were averaged to obtain one value for each participant under each experimental condition. Urine specific gravity is dimensionless, and higher values indicate more concentrated urine. |
| Urine Colour Score Assessed Using the Armstrong 8-Point Urine Colour Chart | At the scheduled urine collection time points during each 24-hour experimental condition. | Urine colour was assessed using the Armstrong 8-point Urine Colour Chart. Scores range from 1, indicating very pale urine, to 8, indicating very dark urine. Higher scores indicate darker and generally more concentrated urine. Triplicate assessments were averaged to obtain one urine colour score for each scheduled urine sample. |
| Urinary Nitrogen Excretion | 24-hour urine collection during each experimental condition | Total urinary nitrogen will be measured from 24-hour urine samples and expressed as grams of nitrogen per 24 hours. This value will be used to estimate the contribution of protein metabolism to substrate oxidation calculations. |
| Urinary Creatinine Excretion | 24-hour urine collection during each experimental condition | Urinary creatinine will be measured as a quality control marker for the plausibility and completeness of the 24-hour urine collection. |
Countries
Italy
Outcome results
None listed