Appetite Regulation, Food Preferences, Gut Microbiota, Overweight (BMI > 25), Satiety and Food Intake
Conditions
Keywords
Alternative Proteins, Edible Insects, Hemp Protein, Legume Protein, Appetite Regulation, Overweight, Novel Foods, Microalgae (Protein), Food Acceptability, Satiety, Metabolic Health, Gut Microbiota
Brief summary
This study investigates the effects of foods enriched with alternative protein sources, including edible insects, microalgae, hemp, and legumes, on appetite regulation, satiety, food preferences, and metabolic health in healthy adults and individuals with overweight. The study is part of the CIPROMED project, which aims to support sustainable and circular food systems in the Mediterranean area. The study consists of two phases. In the acute phase, participants will consume different protein-enriched bread products in a controlled setting following a randomized crossover design. Each participant will be exposed to multiple test conditions, allowing within-subject comparisons of postprandial responses. Outcomes assessed during this phase include satiety, hunger, food preference, craving, and short-term energy intake, measured using validated scales and dietary assessment tools. In the chronic phase, participants will follow structured dietary interventions over a longer period within a Mediterranean dietary framework. Participants will be assigned to different dietary patterns including alternative protein-based foods and control products. This phase aims to evaluate the effects of repeated consumption of alternative protein sources on metabolic parameters, gastrointestinal tolerance, nutritional status, and behavioral responses. The study aims to assess the acceptability and physiological effects of alternative protein sources and to compare their impact with that of traditional protein sources commonly used in Mediterranean diets.
Detailed description
The acute phase of the study is designed to evaluate the short-term effects of foods enriched with alternative protein sources on appetite regulation, satiety, and eating behavior. Healthy volunteers and individuals with overweight will participate in a controlled, within-subject crossover study conducted at the Department of Agricultural and Food Sciences (DISTAL), University of Bologna. Participants will attend five test sessions over five consecutive weeks. During each session, participants will consume one of five test products: bread enriched with alternative protein sources (edible insect protein \[Acheta domesticus\], microalgae \[spirulina\], hemp, or legumes) or a wheat-based control bread. All products will be standardized and comparable in terms of energy content. The order of product administration will be randomized according to a Latin square crossover design, ensuring balanced exposure to all test conditions. Randomization will be stratified by gender and weight status (normal weight/overweight). At each test session, participants will undergo assessments of postprandial satiety, hunger, food preferences, craving responses, and short-term energy intake using validated scales and dietary assessment tools. This design allows within-subject comparisons across different protein sources while minimizing potential confounding factors.
Interventions
OTHERMediterranean Diet with Control Products (chronic phase)
Mediterranean diet including control foods such as legume-based bread and standard fish burger, consumed five times per week for a period of 2 months.
OTHERMediterranean Diet with Insect Protein Bread (chronic phase)
Mediterranean diet including bread enriched with edible insect protein (Acheta domesticus), consumed five times per week over a 2-month intervention period.
OTHERMediterranean Diet with Seaweed-Based Burger (chronic phase)
Mediterranean diet including a burger made from edible seaweed, consumed five times per week over a 2-month intervention period.
Sponsors
University of Bologna
IRCCS Azienda Ospedaliero-Universitaria di Bologna
University of Turin, Italy
Azienda Usl di Bologna
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
This is a spontaneous, exploratory, interventional, controlled, open-label, randomized, national multicenter study evaluating novel food prototypes. In the acute phase, healthy volunteers and overweight participants will consume bread enriched with alternative protein sources (edible insects \[Acheta domesticus\], microalgae \[spirulina\], hemp, or legumes) in a controlled setting at the Department of Agricultural and Food Sciences (DISTAL), University of Bologna. In the chronic phase, participants will consume alternative protein-based foods at home, including insect-based bread or seaweed-based burgers. Overweight participants will be enrolled at the Endocrinology Unit of IRCCS Azienda Ospedaliero-Universitaria di Bologna, which will also conduct medical screening and safety monitoring. Healthy volunteers will be enrolled at DISTAL and recruited through institutional advertisements.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Providing signed informed consent, * Being between 18 and 65 years of age, * Having a body mass index (BMI) within the normal range, defined as between 18.5 and 24.9 kg/m² or Having a body mass index (BMI) between 25.0 and 34.9 kg/m², inclusive, corresponding to the overweight category or, at most, class I obesity.
Exclusion criteria
* Positive and documented history of allergy to legumes, insects, microalgae, shellfish, mollusks, crustaceans, snails, insect venom, house dust mites, or any component (ingredient or additive) present in the food prototypes tested, or a confirmed or suspected diagnosis of Celiac Disease. * History of severe allergic reactions to any type of allergen. * Pregnancy or Breastfeeding
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial Satiety Assessed by Visual Analogue Scales (VAS) | At each test session following product consumption (5-week period) | Subjective appetite sensations are assessed using a customized 100 mm Visual Analogue Scale (VAS). The scale evaluates four primary domains: hunger, fullness (satiety), desire to eat, and prospective food consumption. Participants mark a point on a 100 mm line anchored by "not at all" (0 mm) and "extremely" (100 mm). Total scores for each domain range from 0 to 100, where higher scores for satiety indicate a greater feeling of fullness, and higher scores for hunger indicate a greater urge to eat. Post-prandial ratings are measured at baseline and at specific intervals following the consumption of protein-enriched bread products. |
| Food Preference and Craving Responses Assessed by HTAS, LFP, and Hedonic Scale | At each test session following product consumption (5-week period) | Food preference, motivation, and attitudes were assessed following consumption of different protein-enriched bread products using three distinct validated instruments: Health and Taste Attitude Scales (HTAS): The validated Italian version of the HTAS was used to evaluate psychological attitudes toward food. The questionnaire comprises six subscales divided into two dimensions: Health-related attitudes (General health interest, Light product interest, Natural product interest) and Taste-related attitudes (Craving for sweet foods, Pleasure orientation, Using food as a reward). 9-Point Hedonic Scale: Sensory liking of the test foods was evaluated using a 9-point scale ranging from 1 ('Extremely unpleasant') to 9 ('Extremely pleasant'). Leeds Food Preference Questionnaire (LFP): This psychometric tool was used to assess food motivation via food images. It measures two distinct components: 'Liking' (perceived pleasantness) and 'Wanting' (motivation to consume the food at testing). |
| Fasting Blood Glucose | At baseline, 2 months, and 4 months | Fasting plasma glucose concentration, assessed following the dietary intervention with alternative protein sources. Unit of Measure: mg/dL |
| Fasting Serum Insulin | At baseline, 2 months, and 4 months | Fasting serum insulin concentration measured following dietary interventions with alternative protein sources. Unit of Measure: µIU/mL. |
| Serum Triglyceride Levels | At baseline, 2 months, and 4 months | Fasting serum triglyceride concentration measured following dietary interventions with alternative protein sources. Unit of Measure: mg/dL |
| Total Cholesterol Levels | At baseline, 2 months, and 4 months | Fasting serum high-density lipoprotein (HDL) cholesterol concentration measured following dietary interventions with alternative protein sources. Unit of Measure: mg/dL |
| LDL Cholesterol Levels | At baseline, 2 months, and 4 months | Fasting serum low-density lipoprotein (LDL) cholesterol concentration, calculated using the Friedewald formula, measured following dietary interventions with alternative protein sources. Unit of Measure: mg/dL |
| Gastrointestinal Symptoms Assessed by Nepean Dyspepsia Index (NDI) | At baseline, 2 months, and 4 months | Gastrointestinal symptoms were assessed following dietary interventions with different protein sources using the Nepean Dyspepsia Index (NDI). This validated instrument measures symptom severity, quality of life, and the impact of functional dyspepsia on daily living. The study utilizes the version validated through translation from Australian English to Italian. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial Energy Intake and Energy Compensation Assessed by 24-Hour Dietary Recall | Within 24 hours after each test session (5-week period) | Postprandial energy intake and energy compensation measured using 24-hour dietary recall following consumption of different protein-enriched bread products. |
| Incidence of Adverse Events | Within 72 hours after each test session (5-week period) | Participants will complete a 72-hour recall questionnaire to document any adverse reactions they may have experienced following product consumption. |
| Liver Fat Content and Hepatic Stiffness Assessed by FibroScan and Controlled Attenuation Parameter (CAP) | At baseline, 2 months, and 4 months | Liver fat content and hepatic stiffness measured using transient elastography (FibroScan) and Controlled Attenuation Parameter (CAP) to evaluate changes following dietary interventions with different protein sources. |
| Gut Microbiota Composition | At baseline and 4 months | Gut microbiota composition assessed through analysis of fecal samples to evaluate changes following dietary interventions with different protein sources. |
| Appetite Sensations Assessed by Visual Analogue Scales (VAS) | At baseline, 2 months, and 4 months | Subjective appetite sensations are assessed using a customized 100 mm Visual Analogue Scale (VAS). The scale evaluates four primary domains: hunger, fullness (satiety), desire to eat, and prospective food consumption. Participants mark a point on a 100 mm line anchored by "not at all" (0 mm) and "extremely" (100 mm). Total scores for each domain range from 0 to 100, where higher scores for satiety indicate a greater feeling of fullness, and higher scores for hunger indicate a greater urge to eat. Post-prandial ratings are measured at baseline and at specific intervals following the consumption of protein-enriched bread products. |
| Alanine Aminotransferase (ALT) Levels | At baseline, 2 months, and 4 months | Serum alanine aminotransferase (ALT) concentration measured following dietary interventions with different protein sources. Unit of Measure: U/L |
| Aspartate Aminotransferase (AST) Levels | At baseline, 2 months, and 4 months | Serum aspartate aminotransferase (AST) concentration measured following dietary interventions with different protein sources. Unit of Measure: U/L |
| Gamma-glutamyl Transferase (GGT) Levels | At baseline, 2 months, and 4 months | Serum gamma-glutamyl transferase (GGT) concentration measured following dietary interventions with different protein sources. Unit of Measure: U/L |
| Fatty Liver Index (FLI) | At baseline, 2 months, and 4 months | Fatty Liver Index (FLI) score calculated following dietary interventions with different protein sources. Unit of Measure: Score (o "Unitless") |
| Complete Blood Count (CBC) | At baseline, 2 months, and 4 months | Hematological parameters (including red blood cells, white blood cells, and platelets) assessed following dietary interventions with different protein sources. Unit of Measure: cells/µL |
| Serum Creatinine and Urea | At baseline, 2 months, and 4 months | Serum creatinine and urea levels assessed following dietary interventions with different protein sources. Unit of Measure: mg/dL |
| Urinary Renal Markers | At baseline, 2 months, and 4 months | Microalbuminuria and urinary nitrogen levels assessed following dietary interventions with different protein sources. Unit of Measure: mg/24h |
| C-Reactive Protein (CRP) | At baseline, 2 months, and 4 months | Serum C-reactive protein (CRP) levels assessed following dietary interventions with different protein sources. Unit of Measure: mg/L |
| Blood Pressure | At baseline, 2 months, and 4 months | Systolic and diastolic blood pressure assessed following dietary interventions with different protein sources. Unit of Measure: mmHg |
| Serum Immunoglobulin Levels | At baseline, 2 months, and 4 months | Serum immunoglobulin levels (including total IgE) assessed following dietary interventions with different protein sources. Unit of Measure: IU/mL |
| Body Weight | At baseline, 2 months, and 4 months | Body weight measured following dietary interventions with different protein sources. Unit of Measure: kg |
| Body Circumferences | At baseline, 2 months, and 4 months | Body circumferences (including waist, hip, and abdominal) measured following dietary interventions with different protein sources. Unit of Measure: cm |
| Mood Assessed by the Beck Depression Inventory-II (BDI-II) | At baseline, 2 months, and 4 months | Assesses the severity of depressive symptoms following dietary interventions with different protein sources. The BDI-II is a 21-item questionnaire. Total scores range from 0 to 63, where higher scores indicate greater severity of depressive symptoms (worse outcome). Unit of Measure: Score on a scale (0-63) |
| Food Neophobia Assessed by the Food Neophobia Scale (FNS) | At baseline, 2 months, and 4 months | Assesses the reluctance to taste new foods following dietary interventions with different protein sources. The FNS consists of 10 items measured on a 7-point Likert scale, with total scores ranging from 8 to 40. Higher scores indicate an increasing neophobic attitude (worse outcome/reluctance to try new foods). Unit of Measure: Score on a scale (8-40) |
| Food-Related Attentional Bias Assessed by the Pictorial Dot-Probe Task | At baseline and 4 months | Evaluates selective attention towards food stimuli (healthy vs. unhealthy) following dietary interventions with different protein sources. Attentional bias is measured as the reaction time difference (in milliseconds) to probes appearing in the location of emotionally salient food stimuli. Faster reaction times to probes appearing in the location of the food stimulus suggest greater attentional bias. Unit of Measure: milliseconds (ms) |
| Changes in Concomitant Medication Use | At baseline and 4 months | Participants will be asked to provide a detailed account of any medications they are currently taking. |
Countries
Italy
Contacts
CONTACTMaria Letizia Petroni, Professor
PRINCIPAL_INVESTIGATORMaria Letizia Petroni, Professor
University of Bologna
Outcome results
None listed