We aimed to investigate the association of main meals’ specific protein intake with cardiometabolic risk factors, including general and abdominal obesity, serum lipid profile, and blood pressure (BP). This cross-sectional study was conducted on 850 subjects aged 20–59 years. Dietary intakes were assessed by completing three 24-h recalls, and the protein intake of each meal was extracted. Anthropometric measures, lipid profile, fasting blood sugar and BP were measured. Multivariate logistic regression controlling for age, physical activity, sex, marital status, smoking status, BMI and energy intake was applied to obtain OR and CI. The mean age was 42 years, and the mean BMI of the participants was 27·2. The mean protein intake for breakfast, lunch and dinner was 12·5, 22·2 and 18·7 g/d, respectively. After adjustment for confounders, higher protein intake was not associated with any of the cardiometabolic risk factors, including LDL-cholesterol, HDL-cholesterol, total cholesterol (TC), TAG, body weight, BP and fasting plasma glucose, in any of the three main meals consumed within a day. Adherence to a higher protein intake at each meal was not associated with cardiometabolic risk factors in Iranian adults. Further prospective studies are needed to justify our findings.

We have recently shown that meal-induced insulin sensitization (MIS) occurs after feeding and decreases progressively to insignificance after 24h of fasting and is caused by action of a hepatic insulin sensitizing substance (HISS). In order to carry out quantitative studies of MIS, some standardized meal intake is required. Our objective was to establish animal models to be tested in both the conscious and anaesthetized state using intragastric injection of liquid meals in order to quantify MIS. Insulin sensitivity was assessed before and 90min after the meal using the rapid insulin sensitivity test (RIST) which is a transient euglycaemic clamp. Rats tested in the conscious state were instrumented under anaesthesia 6–9d prior to testing with catheters in the carotid artery, jugular vein and stomach. Meals, injected into the stomach, consisted of a liquid mixed meal, sucrose, glucose or water. The glucose sequestration in response to insulin increased by 90% and 61% following the liquid mixed meal (10ml/kg) in conscious and anaesthetized rats, respectively. Glucose, sucrose and water did not effectively activate MIS. MIS was completely reversed in the conscious model by atropine and completely prevented from developing in the anaesthetized model that had previously undergone hepatic denervation. Gastric administration of a liquid mixed meal but not glucose or sucrose is capable of activating MIS for purposes of mechanistic studies and quantification of the MIS process. The feeding signal is mediated by the hepatic parasympathetic nerves.

Performance, water intake and feeding behaviour of two groups of 30 (trial 1), 40 (trial 2) or 50 (trial 3) weaned pigs offered either pellets or meal of the same formulation were compared.

Average daily weight gains (ADG) were higher for pigs given pellets rather than meal in trials 2 (413 v. 363 g/day,

P < 0·001) and 3 (356 v. 324 g/day, P < 0·05). Mean daily water intake (DWI) was higher with meal than with pellets but only during trial 1 (2·31 v. 1·65 I/day, P < 0·01).

The occupation time (ОT) and the number of animals using the feeder simultaneously (N) were higher when pigs were given meal rather than pellets, whatever the animal density: trial 1: 82·6 v. 69·9% (P = 0·05) and 3·8 v. 2·3 (P < 0·01); trial 2: 90·9 v. 77·9% (P > 0·05) and 5·2 v. 3·1 (P < 0·01); trial 3: 96·2 v. 83·6% (P < 0·05) and 5·9 v. 3·8 (P < 0Ό1). When using pellets, ОT and N were always significantly lower during the night than during the day but when using meal in groups of 40 and 50, ОT during the night was almost as high as during the day.

The greater the group size, the lower were ADG (both diets) and DWI (only with meal) and the higher were ОT and N (both diets). Furthermore, significant linear and curvilinear regressions of DWI, ОT and N according to time were calculated.

In conclusion, pigs need more time to eat meal than to eat pellets. Thus the number of pigs per feeder has to be adapted to the food presentation. Too high a number of pigs per feeder impairs feeding behaviour and eventually welfare, by preventing preferential diurnal feeding activity and this may affect productivity.

It is commonly stated that ‘snack’ foods provide ‘empty calories’ and, therefore elevate energy intake whist providing insignificant quantities of other nutrients. The data presented in the present review suggest that foods which contribute to the pattern of ‘snacking’ contribute significantly to the nutrient quality of the diet. Those who ‘snack’ frequently tend to eat more food in general. Part of the difficulty in identifying the nutritional implications of ‘snacking’ is related to the definitions of ‘meals’ and ‘snacks’ and subsequent categorization of individual patterns. The physiological definitions typically relating to energy content or the time of eating do not necessarily coincide with colloquial, cultural or individual perceptions of what constitutes a ‘meal’ or ‘snack’. Clearly, a more consistent approach would facilitate interpretation of the literature and enable more effective health education messages about ‘snacking’ to be delivered.

Ten crossbred boars were penned individually and offered either meal or pellets of identical composition to appetite from single space hopper feeders which also provided water. The hoppers were sited on raised steel mesh platforms 1·2 m × 0·87 m in size under which was placed a similar sized collecting tray. Spilled food was collected for 24 h once weekly for the 4-week experimental period. Live-weight gain tended to be lower on the meal diet compared with the pellets (882 v. 968 (s.e. 28·7); P = 0·07) while food conversion efficiency (g food per g growth) was worse on the meal diet (2·65 v. 241 (s.e. 0·059); P < 0·05). Food spillage is the most likely explanation for the difference in food conversion, however collectable spilled food was (g/g food offered) 0·0089 and 0·0026 respectively of meal and pellets offered. The value for the meal diet is about one-tenth of the expected value and suggests that direct collection of spillage from non-pelleted diets even over a wide area in front of the feeder is not an accurate technique.

Effects of acute (meal) and chronic (diet) level of protein supply on metabolic leucine utilization were investigated in growing (10 weeks) and mature (> 1 year) rats. Rats were conditioned on a high-protein (HP) diet (210 g casein/kg feed) or a low-protein(LP) diet (75 g casein/kg feed) from 7 weeks of age. Overnight-fasted rats were offered a HP or LP meal during a 8 h 14CO2 breath test with a constant infusion of either L-[l-14C]leucine (carboxyl, CL) or L-[U-14C]leucine (universal, UL). Before the meal 14CO2 output was lower for overnight-fasted rats fed on LP than on HP (P < 0·001), and also lower for growing than for mature rats (P < 0·001). Meal ingestion resulted in a rapid increase in 14CO2 output. From 2 h after the start of the meal the effect of acute protein supply on 14CO2 output was significant (P < 0·001), while the effect of chronic protein supply disappeared for CL. After the meal 14CO2 output was transiently lower for growing than for mature rats (P < 0·05), especially after the LP meal. The difference in 14CO 2 output between CL and UL increased transiently after the meal, indicating an increase in decarboxylation relative to total oxidation of leucine. In conclusion: (1) metabolic leucine utilization after overnight fasting depends on the level of chronic protein supply and stage of development of the animal, (2) metabolic leucine utilization after feeding depends primarily on the level of acute protein supply, (3) the transient increase in non-protein label retention suggests a temporal oversupply ofleucine relative to the actual metabolic state.