The Effects of Ready Meal Consumption on Self- reported Appetite Ratings and Subsequent Food Intake in Females

Introduction: Overweight and obesity are public health concerns and there is a\nforecast rise in the consumption of ready meals that are generally high in saturated\nfat and low in fibre (Reimers et al. 2011; WHO, 2018). Slimming World, a commercial\nweight management organisation has designed a range of ready meals in line with\ntheir weight management programme, which advocates an unrestricted intake of low\nenergy dense food in order to aid in weight loss. Hence, it is valuable to understand\nthe satiating properties of ready meals in order to establish if specific ready meals\ncan enhance satiety and contribute to reducing subsequent energy intake. This thesis\nwill explore the effect of ready meals on short-term satiety and food intake among\nfemales with a BMI ≥ 25 kg/m2. Methods: In two separate studies a total of 38 female participants (Study One: n= 26,\nStudy Two: n= 12), aged between 18-65 years attended Oxford Brookes Centre for\nHealth and Nutrition for two separate testing days. Study One aimed to investigate\nthe effects of energy matched ready meals (calorie-matched but differing quantities\nof protein and fat), whilst Study Two aimed to explore the effects of fixed portion size\n(differing in calories and fat, with similar protein) ready meals on appetite and\nsubsequent energy and macronutrient intake. The ready meals (Control =\nSainsbury’s, Test = Slimming World) differed in energy density and macronutrient\ncomposition, with satiety responses investigated in the studies. For both studies,\nparticipants consumed a standard breakfast and four hours later consumed either a\ntest ready meal (lasagne, higher energy density) or the control ready meal (lower\nenergy density). Four hours after lunch participants food intake was measured during\nan ad libitum buffet tea. Additionally, satiety measurements were recorded using\nvisual analogue scales throughout and participants completed a weighed food diary\nfor the remainder of the test day. Results: Study One revealed that the test meal significantly reduced hunger (p=\np<0.001), desire to eat (DTE; p<0.01) and prospective consumption (p=0.001), whilst\nfullness (p<0.001) increased compared to the control meal between lunch and the buffet tea. There was no significant difference between energy intake between the\ntwo ready meals during the buffet tea (p=0.10), however, during the whole testing\nday the test meal provided significantly less fat and saturated fat (both p<0.01), but\nsignificantly more carbohydrates, sugars, fibre, protein and salt (all p<0.01) compared\nto the control day. In Study Two, appetite ratings between lunch and buffet tea\nindicated no difference between the two meals for hunger (p=0.06) but fullness was\nsignificantly greater (p<0.01) after consuming the control meal. DTE and prospective\nconsumption were significantly greater after consuming the test meal (p=0.01 &\np=<0.01, respectively). Whole day food intake showed a significant reduction in\nenergy intake (~873 kcal; p=0.05), fat and saturated fat (both p=0.00) for the test day\nbut there were no differences between test and control days regarding carbohydrate,\nsugars, fibre, protein and salt (all p>0.05) consumption. Conclusion: Both of these studies found that in the instance of subsequent shortterm\nenergy intake, there was no significant difference between the two ready meals,\ndespite indicating beneficial subjective satiety responses. Nevertheless, these ready\nmeals are important for aiming to improve nutritional guidelines e.g. reduced fat,\nespecially if the forecast increase in ready meal consumption does occur. It may be\nbeneficial for weight management organisations to continue to promote\nconsumption of ‘satiety-enhancing’ ready meals over standard ready meals in order\nto lower fat, potentially impacting long-term energy balance and overall health but\nlongitudinal studies would need to be conducted.