Impact of Sweeteners on Behaviour, Physiology & Health

This protocol has the overall objective to evaluate the acute (short-term, 1 day) and repeated (medium-term, 2 week) effects of combinations of sweeteners and sweetness enhancers (S&SEs) on metabolic, sensory, neuro-behavioural and microbiota-mediated processes involved in satiety, consumer preference and health, and to explore mechanistic processes, genetic background, safety issues and consumer perspectives.

There are 5 products being tested in 3 different formulations (sucrose-sweetened control vs 2 reformulated with S&SE). Each product will be tested at 2 intervention sites in double-blind cross-over trials with 48 subjects (24 per site) tested per product. Therefore a total of 240 subjects will take part across the 5 intervention sites (Navarra, Leeds, Liverpool, Copenhagen, Lyon).

Using identical procedures each trial will consist of 2 Clinical Investigation Days (CIDs) scheduled 12 days apart for each of the 3 product formulations. A 2-week wash-out period will be given between formulations.

The total duration of WP2 Phase 2 is 12 months, including a 5-month duration for each cross-over trial.

Inclusion criteria

• BMI: 25 to 35 kg/m2
• Use of contraceptive methods or not planning to become pregnant for the duration of the study (women only)
• Regular consumption of sugar-containing foods and willing to consume sugar and artificially-sweetened food products.
• Liking of the intervention foods defined by a response of Yes for the product during the pre-screening interview and a score of 40% or above on the Liking Visual Analogue Scale for the sucrose-sweetened control product.
• Able to participate on the Clinical Investigation Days during normal working hours.
• Healthy as determined from the self-reported medical history or when a clinical condition exists, when this is considered to be irrelevant (i.e. not influencing study outcomes) for the study by the study medical doctor.
• Consuming breakfast regularly (at least 5 days per week).
• Able to understand and be willing to sign the informed consent form, and to follow all the study procedures and requirements.
• Capacity to store at-home intervention quantity of intervention product

Exclusion criteria

• Blood donation < 3 month prior to study or for full duration of the study.
• Food allergy, intolerance, restriction or avoidance of any of the study foods (e.g. veganism) or history of anaphylactic reaction to any food.
• Likelihood for disordered eating defined as a score ≥20 on the Eating Attitudes Test.
• Currently dieting to lose weight.
• Having lost or gained >4.5 kg in the last 3 months.
• Smoking or having quit <3 months prior to study.
• Habitually consuming >14 units/week of alcohol in women or >21 units/week in men in the last 3 months.
• Performing >10 h of intense physical activity per week in the last 3 months.
• Night or late shift work (ending later than 11 pm on a permanent basis). Rotational shift work allowed if can attend on days that do not follow a late/night shift.
• Self-reported use of drugs of abuse within the previous 12 months.
• Pregnancy, lactation (women only)
• Persons who do not have access to either (mobile) phone or internet (this is necessary when being contacted by the study personnel during the study).
• Insufficient communication in the national language.
• Proven or suspected inability, physically or mentally, to comply with the procedures required by the study protocol as evaluated by the daily study manager, site-PI, PI or clinical responsible. This includes volunteers for which insufficient collaboration may be foreseen.
• Subject's general condition contraindicates continuing in the study as evaluated by the daily study manager, site-PI, PI or responsible clinician.
• Simultaneous participation in other relevant clinical intervention studies.
• Previous university or college training related to eating behaviour research.
• Self-reported eating disorders.
• Diagnosed anaemia.
• Diagnosed diabetes mellitus.
• Abnormal G.I. function or structure such as malformation, angiodysplasia, active peptic ulcer.
• Active inflammatory bowel disease, celiac disease, chronic pancreatitis or other disorder potentially causing malabsorption.
• History of G.I. surgery with permanent effect (i.e. surgical treatment of obesity).
• Medical history of Cardiovascular Disease (e.g. current angina; myocardial infarction or stroke within the past 6 months; heart failure; symptomatic peripheral vascular disease).
• Significant liver disease, e.g. cirrhosis (fatty liver disease allowed).
• Malignancy which is currently active or in remission for less than five years after last treatment (local basal and squamous cell skin cancer allowed).
• Thyroid diseases, except those on Levothyroxine treatment of hypothyroidism if the person has been on a stable dose for at least 3 months.
• Psychiatric illness (e.g. major depression, bipolar disorders).
• Use currently or within the previous 3 months of prescription or over the counter medication that has the potential of affecting appetite, satiety or body weight incl. food supplements. Except: low dose antidepressants if they, in the judgement of the daily study manager, site-PI, PI or clinical responsible, do not affect weight or following the study protocol. Levothyroxine for treatment of hypothyroidism is allowed if the person has been on a stable dose for at least 3 months.
• Cholesterol lowering medication, if the dose has changed during the last 3 months (i.e. the medication is allowed if the participant has been on a stable dose for at least 3 months).