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HealthyNCT07247513

Glycaemic Responses to a Food Intake Sequence Intervention in Free-living Elite Female Athletes

A study testing Carbohydrate-last meal pattern and Carbohydrate-first meal pattern in people with Healthy and Nutrition, run by Universidade do Porto at 1 site in Portugal.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The goal of this clinical trial is to investigate the impact of a food intake sequence intervention under free-living conditions on glycaemic responses in elite female athletes. Specifically, the main questions it aims to answer are: 1. Read more about this study

Who is it for?
Ages 18 to 64 years, women onlyHealthy volunteers can take part
Conditions the study is for
Healthy, Nutrition, Glycemic Variability
What is being tested?
Carbohydrate-last meal pattern and Carbohydrate-first meal pattern
Could I receive a placebo?
No, everyone receives an active treatment
How many people
22 participants
Where
1 sitePortugal
Study dates
24 Nov 2025to 29 Nov 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 64 years
  • Women only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Adult (18-64 years old)
  • Women
  • Elite athletes (meeting training and performance caliber criteria ≥Tier 4; McKay et al., 2022)
  • Healthy (meeting the exclusion criteria for medical conditions)
  • Normal glucose tolerant according to the latest review standards of the American Diabetes Association (ElSayed et al., 2024): HbA1c <5.7%, fasting plasma glucose <5.6 mmol/L (100 mg/dL), or 2-h plasma glucose <7.8 mmol/L (140 mg/dL) during a 75-g OGTT
  • Able and willing to provide informed consent and safely comply with study procedures

Who cannot join

  • Any medical condition or behaviour deemed either to pose undue personal risk to the participant or introduce bias into the experiment (e.g. pregnancy, alcohol or substance abuse; any condition affecting the glucose and lipid metabolism or appetite, reviewed on a case by case basis)
  • Any reported medication or supplementation that may interfere with the glucose metabolism (e.g., acarbose, aspirin, berberine, insulin, metformin, semaglutide, sulfonylureas, thiazide diuretics, thiazolidinediones, vitamin C). Other medication and supplementation will be reviewed on a case by case basis.
  • Recent change in body mass (± 2 kg in the last 2 months)
  • Smoking

Trial locations and contacts

1 site in 1 country.

Portugal1 site
  • Cidade do Futebol

    Oeiras, Lisbon District, 1495-433

Other trials in Portugal

About this study

Official title: Glycaemic Responses to a Food Intake Sequence Intervention Under Free-living Conditions in Elite Female Athletes

The goal of this clinical trial is to investigate the impact of a food intake sequence intervention under free-living conditions on glycaemic responses in elite female athletes. Specifically, the main questions it aims to answer are:

  1. Does consuming breakfast in different food intake sequences alter postprandial interstitial glucose responses?
  2. Does consuming a pre-exercise meal in different food intake sequences alter interstitial glucose responses during exercise?
  3. Does consuming the last meal of the day in different food intake sequences alter nocturnal interstitial glucose responses?
Read more

To address these questions, researchers will compare eating the dietary sources of rapidly absorbed carbohydrate (CHO) at the end (CHO-last meal pattern) or at the start (CHO-first meal pattern) of standardised mixed meals, at different times of day, in a randomised, counterbalanced, crossover design.

Participants will wear a blinded continuous glucose monitor (CGM) for 6 consecutive days during a training camp. Throughout the study, they will be provided with buffet meals, at the same time and location each day. Dietary intake will be ad libitum, except for breakfast and supper, for which participants will select a preferred composition (ingredients, preparation methods, portion sizes) to replicate across study days. In all ad libitum meals (i.e., lunch, snacks, and dinner), they will be asked to maintain their assigned food intake sequence.

  • On day 1, athletes will eat freely. An educational session on the study protocol and food sequence manipulation will be delivered, and informed consent, questionnaires, screening assessments, and CGM fitting will be completed. Data collected by the CGM during the first 24 hours will be disregarded due to sensor stabilisation. Hence, this period will serve for familiarisation only.
  • On days 2 and 3, one group will eat the last meal of the day (i.e., supper) in a CHO-last meal pattern, while the other will follow a CHO-first meal pattern; on days 3 and 4 one group will eat breakfast in a CHO-last meal pattern while the other will follow a CHO-first meal pattern.
  • On days 4 and 5 (supper) and 5 and 6 (breakfast), participants in each group will adhere to the alternate condition.

Concurrent data on potential confounding factors (e.g., dietary intake, physical activity, internal and external load during training sessions/competition, sleep quantity and quality, menstrual cycle phase/status) will be collected.

Due to the short camp duration, implementing a one-day washout period will not be feasible. Therefore, repeated measurements over two consecutive days per condition will be obtained to minimise carryover effects of the food intake sequence from prior meals on end-of-intervention data (the final 24 hours per condition), and to assess intraindividual consistency of outcomes at matched-times and standardised settings.

Glycaemic responses will be compared within-participant between food intake sequences using linear mixed models with random intercepts, to account for repeated measures, interindividual variability, and potential missing data.

Being tested
Carbohydrate-last meal pattern, Carbohydrate-first meal pattern
Keywords
food order, meal sequence, glycaemia, sport nutrition
Medical subject headings
Motor Activity

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Carbohydrate-last meal patternOther

    Also called CL, CHO-last

    Participants will consume the main dietary sources of protein, fat, fibre and/or polyphenols before the main dietary sources of simple carbohydrate in the standardised test-meals (breakfast and supper) and will be encouraged to maintain this food intake sequence in the remaining meals of the day.

    Participants will be instructed to consume lunch and dinner within 30 min, and breakfast and supper within 15 min at a comfortable pace, without intervals between the carbohydrate and non-carbohydrate-rich meal components.

  • Carbohydrate-first meal patternOther

    Also called CF, CHO-first

    Participants will consume the main dietary sources of protein, fat, fibre and/or polyphenols after the main dietary sources of simple carbohydrate in the standardised test-meals (breakfast and supper) and will be encouraged to maintain this food intake sequence in the remaining meals of the day.

    Participants will be instructed to consume lunch and dinner within 30 min, and breakfast and supper within 15 min at a comfortable pace, without intervals between the carbohydrate and non-carbohydrate-rich meal components.

Study groups in NCT07247513
Study groupRoleWhat they receive
CL - CFExperimentalThe interventions (carbohydrate-last meal pattern (CL) or carbohydrate-first meal pattern (CF)) will be delivered in random order. If participants are allocated to this study arm, they will receive the CL on the first 2 days and the CF on the next 2 days of the study period.
Receives: Other: Carbohydrate-last meal pattern; Other: Carbohydrate-first meal pattern
CF - CLActive comparatorThe interventions (carbohydrate-last meal pattern (CL) or carbohydrate-first meal pattern (CF)) will be delivered in random order. If participants are allocated to this study arm, they will receive the CF on the first 2 days and the CL on the next 2 days of the study period.
Receives: Other: Carbohydrate-last meal pattern; Other: Carbohydrate-first meal pattern

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incremental interstitial glucose peak after a standardised test meal

    Difference between CHO-last and CHO-first meal patterns in the incremental interstitial glucose peak (mmol/L) adjusted for baseline, following standardised breakfasts (independent of and coinciding with subsequent exercise) and the end-of-intervention (days 3 and 5) standardised supper, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 0-120 minutes following a standardised test meal

Secondary outcomes (11)
  1. Incremental area under the interstitial glucose curve after a standardised test meal

    Difference between CHO-last and CHO-first meal patterns in the incremental area under the interstitial glucose curve (mmol/L x min) adjusted for baseline, following standardised breakfasts (independent of and coinciding with subsequent exercise) and the end-of-intervention (days 3 and 5) standardised supper, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 0-120 minutes following a standardised test meal

  2. Time-to-peak interstitial glucose after a standardised test meal

    Difference between CHO-last and CHO-first meal patterns in the time-to-peak interstitial glucose (minutes), following standardised breakfasts (independent of and coinciding with subsequent exercise) and the end-of-intervention (days 3 and 5) standardised supper, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 0-120 minutes following a standardised test meal

  3. Time out of interstitial glucose range after a standardised test meal

    Difference between CHO-last and CHO-first meal patterns in the time spent >7.8 mmol/L and time <3.9 mmol/L (%), following standardised breakfasts (independent of and coinciding with subsequent exercise) and the end-of-intervention (days 3 and 5) standardised supper, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 0-180 minutes following a standardised test meal

  4. Interstitial glucose dip after a standardised test meal

    Difference between CHO-last and CHO-first meal patterns in the 2-3-hour interstitial glucose dip (mmol/L), following standardised breakfasts not coinciding with subsequent exercise, and the end-of-intervention (days 3 and 5) standardised supper, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 0-180 minutes following a standardised test meal

  5. Interstitial glucose concentrations during specific activities

    Difference between CHO-last and CHO-first meal patterns in the mean interstitial glucose concentrations (mmol/L) across 15-minute averages and adjusted for baseline where relevant, during the following periods: after standardised breakfasts (independent of and coinciding with exercise); after the end-of-intervention (days 3 and 5) standardised supper, during exercise not coinciding with postprandial periods, during evening sleep, and during daytime rest, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 24 hours

  6. Within-day standard deviation of interstitial glucose

    Difference between CHO-last and CHO-first meal patterns in the 24-hour standard deviation (SD) of interstitial glucose concentrations during the end-of-intervention monitoring period (days 3 and 5), assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ sensor).

    Measured: 24 hours

  7. Within-day coefficient of variation of interstitial glucose

    Difference between CHO-last and CHO-first meal patterns in the 24-hour coefficient of variation (%) of interstitial glucose concentrations during the end-of-intervention monitoring period (days 3 and 5), assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ sensor).

    Measured: 24 hours

  8. Mean amplitude of glycaemic excursions (MAGE)

    Difference between CHO-last and CHO-first meal patterns in the mean amplitude of glycaemic excursions (MAGE) during the end-of-intervention monitoring period (days 3 and 5), assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ sensor).

    Measured: 24 hours

  9. Large amplitude of glycaemic excursions (LAGE)

    Difference between CHO-last and CHO-first meal patterns in the large amplitude of glycaemic excursions (LAGE) during the end-of-intervention monitoring period (days 3 and 5), assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ sensor).

    Measured: 24 hours

  10. Within-day time out of interstitial glucose range

    Difference between CHO-last and CHO-first meal patterns in the time spent >7.8 mmol/L and <3.9 mmol/L (%) over 24 hours during the end-of-intervention monitoring period (days 3 and 5), assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ sensor).

    Measured: 24 hours

  11. Between-day glycaemic variability

    Difference between CHO-last and CHO-first meal patterns in the mean of daily differences (MODD) of interstitial glucose responses at matched clock times, assessed using a blinded continuous glucose monitoring system (Freestyle Libre Pro IQ).

    Measured: 24 hours

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Nov 2025
  2. Study start24 Nov 2025
  3. Primary completion29 Nov 2025
  4. Study completion29 Nov 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Model description
This trial is designed as a randomised, counterbalanced, crossover, open label, superiority trial with two groups. Block randomization will be performed by an external researcher with a 1:1 allocation ratio, and allocation concealment will be ensured through the use of sequentially numbered, opaque, sealed envelopes.
Masking
None (open label)
Enrolment
22 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07247513
Sponsor's protocol ID
FOODSEQ-GRFA
Other IDs
2022.12954.BD
Status last verified
Dec 2025
First submitted
14 Nov 2025
Last updated
5 Dec 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Anonymised IPD will be made available upon reasonable request directed to the corresponding author.

Questions about this trial

What is this clinical trial studying?

A study testing Carbohydrate-last meal pattern and Carbohydrate-first meal pattern in people with Healthy and Nutrition, run by Universidade do Porto at 1 site in Portugal.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 5 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incremental interstitial glucose peak after a standardised test meal (time frame: 0-120 minutes following a standardised test meal). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Dec 2025; AzTrials last refreshed its copy on 26 Oct 2026.

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