4. Discussion
inflammation, satiety, diabetic complications, eating
INFLAMMATION, SECONDARY, DIABETIC COMPLICATIONS, SEPARATION, OXIDATIVE STRESS
Partial equi-carbohydrate exchange of KF for WB at any time within the 120 min time band tested, from 90 min before to 30 min after WB ingestion (treatments 2–5, In terms of energy and dietary fibre content the treatments involving WB and KF (2–5) were similar to the WB74 treatment, although they differed in protein content (The present results showed that any separation of intakes that resulted in separation of the glycaemic responses to each component reduced the peak height by preventing the addition of responses. And if the responses can be separated within the time period in which the KF fibre and organic acids can interact with cereal digestion to reduce glycaemic response, a further reduction could be expected.In the case of KF-90/WB (treatment 2), blood glucose concentrations, with the help of the insulin response, had returned to baseline after about 60 min, while most of the effects of organic acids and fibre on gastrointestinal processes affecting glucose absorption would have been completed by the time of WB ingestion 90 min after KF. Therefore, given that all meals had the same carbohydrate content, and the separation of WB and KF probably eliminated gastrointestinal effects of KF on WB digestion and absorption, the main reason that KF-90/WB induced a lower glycaemic response (iAUC) than WB 74 would probably have been the partial substitution of fruit sugars (containing fructose, GI 22) for starch (GI 70 in WB). When the KF was ingested as a 30 min preload to the WB (treatment 3, KF-30/WB), there were several factors that may have contributed to the substantially reduced response. Firstly, the partial substitution of fructose for glucose. Secondly, the KF organic acids and dietary fibre would have been present and active in the stomach before and from the time of ingestion of the WB, possibly leading to a suppression of salivary amylase activity in the stomach [When the WB and KF were consumed together (KF/WB, treatment 4), the same factors as in the KF-30/WB treatment would have operated except that the glycaemic responses to the KF and WB available carbohydrate would have coincided. The amount of carbohydrate absorbed in both treatments was the same, except that the total carbohydrate load in the KF/WB treatment was ingested as a single load, and the response amplitude was correspondingly higher, without much difference in the total IAUC.When the WB was ingested 30 min before the KF component, there would have been time for most of the glycaemic response to WB to have developed before any of the KF components, such as organic acids and dietary fibre, could have inhibited the digestion of WB starch and/or its delivery to the small intestine. Furthermore, as the cooked starch in WB has a greater intrinsic glycaemic potency than fruit sugars in KF, most of the potential glycaemic response to the combination of KF and WB would have developed free of KF inhibition.A treatment involving the ingestion of 200 g of kiwifruit at 10 pm the evening before consuming 74 g of wheaten biscuit (Treatment 8, KFon/WB74) was included to test for a second meal effect within a manageable time frame. The gap between the ingestion of the 200 g KF and the 74 g of WB was 10 h. The glycaemic responses to WB74 with and without the kiwifruit were almost identical (treatments 1 and 8, The temporal separation of fruit and cereal in the present study did not achieve large reductions in the total areas under the blood glucose response curve, but did achieve significant reductions in peak height. It is now considered that glycaemic response amplitude is an important factor in the damage caused by postprandial glycaemia, leading to diabetic complications through the related processes of glycation, oxidative stress, and inflammation [Although the total amount of satiety did not differ between treatments, all treatments had a satiating effect. The incremental satiety results suggest that if KF is to be used in a carbohydrate exchange format, consuming the KF at about 30 min before WB would have the benefit of combining the satiety effects of the two components while disengaging their peak glycaemic responses. Although it is not easy to translate the satiety scores directly into human behaviour, the satiety results (A possible criticism of using fruit for cereal exchange is that increased fruit intake leads to increased intake of fructose, which has been associated with harmful metabolic and health effects through products of its metabolism, such as uric acid, and through its reactivity in forming advanced glycation end products [A limitation of the present study was that the resources available limited the number of secondary outcomes, such as hormonal changes, that were measured. However, in a previous study on the interaction of WB and KF, we showed that the glycaemic response to both WB and KF, and combinations of the two, were followed very closely by insulin [In terms of meal construction and dynamics, a 30 min separation of food components is not unreasonable and is certainly consistent with the suggestion that “slow food” is a healthier form of eating than consuming large meals quickly [There is more research required on the place and role of fruit in meals, especially on the influence of different types of food on the antiglycaemic effectiveness of fruit components. Perhaps not only the separation of responses, but also the separation of meal items could be used to reduce meal glycaemic potency.