Al Dente or Well Done? The Eating Rate of a Pasta Meal Modified by Texture

The study has a randomized crossover design with three test sessions. All participants receive twelve pasta samples (four per test session) and are their own control (within subject effects).

Participants attend three test sessions during which they eat four pasta samples. The pasta samples will have a fixed amount and differ in pasta noodle and vegetable hardness. Eight pasta samples will consist out of only penne or carrots with or without sauce. Four pasta samples will consist out of penne, carrots, and sauce. The sample order will be randomized, but in each test session only one or two of sample 9 to 12 will be served. The samples will be served on a plate together with a fork.

Procedure of the study:

Throughout study period :

• No use of drugs
• Medication use + illness should be reported

Evening preceding test day:

• Not allowed to eat or drink after 22.00 except for water

Morning of test day:

• Do not perform intensive exercise
• Eat the same breakfast at the same time each test day
• If wanted, eat the same morning snack at the same time each test day
• Not allowed to eat or drink two hours prior the study session except for water
• Have a negative corona test

Lunch

• Give instructions (eat as you normally would do, eat the whole sample without taking breaks or sips of water in between, you can take a new bite before you swallowed the previous one)
• Seated at sensory booth with fork, knife, spoon, 200 mL of water and three pieces of a plain cracker
• Question about food consumption that morning
• Appetite questionnaire
• Eat the pasta sample (one of twelve conditions) while recording eating behavior
• Sensory questionnaire
• Appetite questionnaire
• Taste neutralization by waiting for two minutes, taking sip of water and bite of cracker
• Repeat * ... * until four pasta samples are consumed
• Appetite questionnaire

Participants will be recruited from Wageningen and surroundings using an e-mailing list, social media, and flyers. Healthy (self-report), normal weight (18.5-30 kg/m2) men and women between 18-55 years old will be included. Participants need to have European nationality, and have to be able to understand and speak English (self-report), because of the sensory questionnaire and appetite questionnaire which will be in English and have difficult direct translations to Dutch. As 90% of the people that show interest in the study are university students this should not be a problem. The BMI range is based on the average BMI in the Netherlands, which is 25 kg/m2 but around 50% of the Dutch population is overweight. To be able to include sufficient subjects it was therefore chosen to widen the BMI range and include people up to a BMI of 30 kg/m2. Due to the within subject design this will not influence the outcome of the study, but results will be more generalizable to people with an average weight.

Inclusion criteria

• Between 18-55 years old at the day of inclusion
• European nationality
• Able to understand and speak English fluently or without difficulty (self-report)
• BMI 18.5-30 kg/m2 (self-report)
• Good general health and appetite (self-report)
• Regular consumers of pasta with tomato sauce (commonly once or more per month)

Exclusion criteria

• Pregnant or lactating women
• Smoking
• Braces (not including a dental wire) or oral piercing
• Difficulties with swallowing, chewing and/or eating in general
• Suffering from an endocrine or eating disorder, gastrointestinal illness or illness of the thyroid gland, respiratory disease, or diabetes
• Having taste or smell disorders (self-report)
• Use of medication that may influence study outcomes (self-report)
• Consuming on average more than 21 glasses of alcohol per week
• Not willing to stop using drugs during the study period (from inclusion till last test session)
• Intensive exercising more than eight hours per week
• Allergies or intolerance to any ingredient of the test meals
• Don't like pasta with tomato sauce or its ingredients (<five on a nine point Likert scale)
• Men having facial hair such as a beard as facial movements cannot be analyzed
• Signed up for participating in another research study
• Employee of Human Nutrition department of Wageningen university
• Employee, thesis student or intern at the chair group of Sensory Science and Eating Behaviour Human Nutrition or Food Quality and Design (WUR)