The present study shows that intact pea protein is more satiating than its digested products. However, we do not know whether the subjects compensated the decreased portion size with an increased portion size during the next meal. Also, the amount of protein given is relatively high. Subjects received 250 mg per kg of bodyweight, which is comparable with a fourth of the daily total protein intake. It has previously been demonstrated that this amount of protein affects satiety, and therefore, this amount was also used in the present study. However, future Publications Using Abomle AG490 studies should be designed to identify the lowest effective dose of this protein. Also, options for delivering intact proteins to the duodenum will have to be investigated. There are some studies describing coatings for enteric delivery, such as pH-triggered coatings, pressuresensitive coatings, or time-release coatings. For duodenal delivery of a large amount of protein, a pH-sensitive coating seems suitable. It should be noted that, under physiological circumstances, little intact protein will reach the duodenum. Administering large amounts of intact protein to the duodenum might result in decreased feelings of well-being. Here we demonstrated that these amounts of protein did not affect feelings of nausea, stomach ache, diarrhoea and other factors of wellbeing. As was demonstrated in the past, undigested lipids infused more distal in the ileum caused similar effects. This phenomenon called ��ileal brake�� could also be active in the present situation of undigested protein proximal in the small intestinal tract. The exact mechanisms are still not fully explained as in the lipid infusion studies as in our intact protein infusions not all gut hormones respond similar in relation to satiety response. Other local neurohumoral factors could be involved. There are indications that obese subjects are less sensitive for satiety signals compared to lean subjects. In rats it was shown that the minimal effective dose of satiety hormones was 3�C4 times greater in obese than in lean rats. Here we demonstrated that after the same protein load, CCK levels in obese subjects were higher when compared to lean subjects, whereas GLP-1 and PYY levels did not differ between both groups. This would indicate that there is an impaired balance between protein load sensitivity and release of CCK in obese subjects. Even though the CCK levels were higher, both lean and obese subjects decreased food intake following protein ingestion to the same extent. This suggests that obese subjects are less sensitive to the satiety signals. Although there are no indications that age might have an influence on the present results, we should take into consideration, that even though not significant, there is a trend that there is a age difference between lean and obese subjects used in the present study. We should also take into consideration that perhaps obese subjects are also more sensitive to external cues that influence the amount of food eaten. Hence, the laboratory setting may have influenced eating behaviour in the obese subjects to a larger extent than the lean. However, there were no significant differences between lean and obese subjects in relation with the appetite ratings. VAS are often used to measure subjective appetite sensations and the validity and reproducibility has been shown in several studies. Both groups showed the same changes over time, which may also explain why both groups consumed the same amount of food.