TL;DR: This paper provides a rationale for determining which foods are included within advice--for example, processed foods such as baked beans are but potatoes and nuts should not be, and describes how much of the most commonly consumed fruit and vegetables constitutes a "portion."
Abstract: Consumers need health information which is clear and unambiguous. Advice to "eat more fruit and vegetables" gives consumers no guidance on the quantities involved. Popular advice is to eat "five portions a day." This paper provides a rationale for determining which foods are included within this advice--for example, processed foods such as baked beans are but potatoes and nuts should not be. It also describes how much of the most commonly consumed fruit and vegetables constitutes a "portion." A bowlful of salad, for example, is needed to make up a portion but an apple or banana on its own will count.
TL;DR: The addition of foodstuffs to the staples baked potato, pasta and toast had a consistent lowering effect on the GI value of that meal, highlighting the importance of investigating the GI of composite meals.
Abstract: To investigate the influence of the addition of various toppings/fillings on the glycaemic response to baked potato, pasta and toast. Randomised, repeated measures design. Oxford, UK. Forty normal, healthy subjects (11 males and 29 females) were recruited to the study. Subjects were staff and students from Oxford Brookes University. Cheddar cheese, chilli con carne, baked beans and tuna were added to baked potatoes, cooked pasta and toast to determine the effect on glycaemic response. No significant difference was found among the various toppings and baked potato (P=0.06), pasta (P=0.06) and toast (P=0.39). However, the addition of toppings to a carbohydrate-rich food had a consistent lowering effect on glycaemic index (GI). In particular, the addition of cheddar cheese to potato, pasta and toast reduced the GI of the test meal to a value that is considered to be low-GI (39, 27 and 35, respectively). This is particularly notable for potatoes, which, when eaten alone, had the highest GI value of all the staples. This study has shown that the addition of foodstuffs to the staples baked potato, pasta and toast had a consistent lowering effect on the GI value of that meal. These findings emphasise the importance of investigating the GI of composite meals. British Potato Council.
TL;DR: The benefits of a legume-rich diet are discussed in this paper, where the authors show that beans and spaghetti led to a significant reduction in the amount of fat eaten daily (P less than 0.05).
Abstract: 1. Thirteen normo-cholesterolaemic male students consumed one 450 g can of baked beans (Phaseolus vulgaris) in tomato sauce, daily, for 14 d as part of their normal diet. After a 14 d washout period, eleven of the students went on to consume one 440 g can of spaghetti in tomato sauce, daily, for 14 d. 2. Fasting blood samples were taken frequently for measurement of plasma cholesterol, high-density lipoprotein (HDL)-cholesterol, triacylglycerols, glucose, insulin and C-peptide. Diet diaries (3 d) were completed by the subjects during each period. 3. Consumption of beans and spaghetti led to a significant reduction in the amount of fat eaten daily (P less than 0.05). Bean consumption also resulted in significant increases in protein, fibre and sugar intakes (P less than 0.02, P less than 0.001 and P less than 0.05 respectively). 4. During the bean-eating period the mean total plasma cholesterol level of the students fell significantly from 5.1 to 4.5 mmol/l (P less than 0.02). No reduction in plasma cholesterol occurred during the spaghetti-eating period. 5. HDL-cholesterol levels fell significantly during both periods (P less than 0.001), but HDL:total cholesterol ratio was significantly reduced only during the spaghetti-eating period (P less than 0.001). Neither beans nor spaghetti affected triacylglycerol, insulin or C-peptide levels. 6. The benefits of a legume-rich diet are discussed.
TL;DR: The results suggest that the mechanism for the hypocholesterolaemic effect does not involve increased hepatic bile acid synthesis and thereby increased cholesterol clearance via the intestinal route, although HDL-cholesterol levels were maintained.
Abstract: The effect of four species of legume seeds on plasma cholesterol levels and faecal steroid excretion was studied in pigs. Thirty-six growing boars were randomly allocated in groups of six to six diets which they ate continuously for 42 d. The diets fed were: 1, a semi-purified (SP; control group 1) diet; 2, SP 10 g cholesterol/kg (control group 2); 3, 4, 5, 6, SP + cooked legumes (70:30, w/w; respectively baked beans (Phaseolus vulgaris), peas (Pisum sativum), lentils (Lens culinaris Medik.), butter beans (Phaseolus lunatus)) + 10 g cholesterol/kg. Fasting blood samples were taken on days 0, 14, 28, and 42 for the determination of total plasma cholesterol, high-density-lipoprotein (HDL)-cholesterol and triacylglycerols. Between days 7 and 11 and days 28 and 32 complete 5 d faecal collections were made for the measurement of neutral, acidic and conjugated steroids. After 42 d total cholesterol and HDL-cholesterol levels were raised significantly in all groups, but to different extents. In comparison with control group 2, diet-induced hypercholesterolaemia was significantly inhibited in the groups consuming baked beans, peas and butter beans, although HDL-cholesterol levels were maintained. Faecal steroid excretion by the legume groups was not significantly different from that of control group 2. The results suggest that the mechanism for the hypocholesterolaemic effect does not involve increased hepatic bile acid synthesis and thereby increased cholesterol clearance via the intestinal route.