Effects of Sourdough Fermented Rye Crisp Bread on Appetite and Postprandial Metabolic Responses

Two commercial whole grain rye crisp breads processed differently (unfermented and sourdough fermented) and a refined wheat control product were tested in the study. The rye crisp bread products contained similar ingredients. All products provide similar amounts of available carbohydrates (about 30g). The total amount of test product is about 50-60g.

The specific primary aim of the study: To conduct a short-term breakfast intervention study in humans (n = 24) to compare the effect of 2 high-fiber rye crisp bread products processed in different ways (sourdough fermented or unfermented) and a refined wheat control crisp bread as part of a normal breakfast on self-rated appetite, postprandial glucose and insulin concentrations. Difference in post-prandial insulin response between products is the primary endpoint.

Secondary aim (conducted if significant effects in the primary endpoint have been demonstrated): To assess changes in hormones and their relation to self-perceived satiety, hunger and desire to eat and to differences in chemical and microstructural composition of the tested foods.

Inclusion criteria

• BMI 18.5-30 kg/m2
• fasting plasma glucose <6.0 mmol/L,
• fasting serum insulin <11 mE/L
• serum TSH <2.5 mIE/L
• plasma LDL <5.3 mmol/L
• fasting plasma triglycerides (p-TG) <1.8 mmol/L
• habitual consumption of breakfast, lunch and dinner

Exclusion criteria

• smokers
• use of medications likely to affect appetite
• medical conditions involving the gastrointestinal tract
• gluten intolerance or food allergies
• physical problems with eating
• dieting or self-reported fluctuations in body weight of more than 10% three months prior to screening recent participation in a dietary study
• pregnancy
• lactation