It is believed that to lead a healthy lifestyle it is important to maintain a balanced diet among other factors such as exercise. However it is not just necessary to have a balanced diet, it must be a combination of healthy and balanced, it requires a lot of mindful decisions to verify that which is being consumed corresponds to the ideal of a "healthy, balanced" diet. The healthy part refers to eating the right amounts of food in correspondence to how active you are whereas balanced refers to the necessity to eat a range of different foods. To view the different types of food you should eat and how much of what is eaten should come from each group see fig.1
What are energy requirements?
When a person eats or drinks, it provides energy to the body in the form of calories. The body then uses up the calories from food for movement, chemical reactions, warmth and a multitude of other necessary functions. Although everybody requires energy, some may require more than others depending on height, weight, age etc. The more physically active a person is, the more energy they require thus the more calories they use. In order to maintain a stable weight, the calorie intake must equal the energy expenditure from physical activity and everyday bodily functions. When someone regularly takes in more calories than they use over a prolonged period of time, the excess is stored by the body as fat, thus the person gains weight. A certain amount of activity must be performed regularly in order to maintain overall health and fitness, to achieve energy balance and to reduce the risk of developing obesity and associated diseases, most of which are associated with a sedentary lifestyle. Also the cultural, social and environmental characteristics of the subject must be taken into account to correctly calculate the necessary energy requirements.
Where do we get our energy from?
Nutrients are required for movement, reparation and growth of the body, the greatest supply of these are found in food. Food undergoes a process involving digestion, absorption, assimilation and excretion. It provides calories that are used within the body to provide energy. Energy is a necessity for the upkeep of breathing, moving, homeostasis and vital organs of the body. The three major nutrients which should make up the largest part of what is eaten are carbohydrates, lipids (Fats) and proteins. Humans also need vitamins and minerals, which are equally as crucial but are only required in small quantities and water is also necessary, which makes up about 60% (by volume) of the food that people eat. Carbohydrates are the main source of energy for all cellular functions, particularly in the brain and central nervous system (CNS). Supplying 4 calories per gram These include sugar, starches and fibre. Sugar can be divided into groups of simple and complex sugars derived from fruits, grains and starchy vegetables. Starches are made of many sugar units linked together. Starches and sugars are good sources of energy in the diet. Fibre provides little energy to the body because it cannot be digested or absorbed. It is, however, important for the health of the gastrointestinal tract.
Lipids are commonly called fat. Fat is a concentrated source of energy in the diet and in our bodies, providing 9 calories per gram of fat. Fats in your body cushion your organs from shock and blunt trauma and stores energy for future use. Most of the fat in our diet and in our body is in the form of triglycerides. Triglycerides provide you with energy during aerobic metabolism and are stored in your adipose (fat) tissues beneath your skin, within skeletal muscles and around your organs. Fats are classified as either saturated fats or unsaturated fats. Saturated fats are usually solid at room temperature and are found mostly in animal products such as meat, milk, and butter. Unsaturated fats are found in vegetable oils and are usually liquid at room temperature. Small amounts of certain unsaturated fatty acids are essential in the diet. Cholesterol is another type of lipid. Cholesterol provides structure for steroid hormones, cell membranes, and bile acids. Within cells, it regulates fluid balance within the cell and its external fluid environment Diets high in saturated fat and cholesterol may increase the risk of heart disease. A type of unsaturated fat called trans fat should also be limited because it promotes heart disease.
Protein, providing 4 calories per gram, is needed for growth, the maintenance and repair of body structures, and for synthesis of regulatory molecules. It can be broken down to provide energy if the body seriously requires it. Proteins provide the basic structures for the organ systems in the body, including muscles, bones, hair, skin, cartilages and circulatory systems. They also provide structures for enzymes. Some proteins, such as antibodies and insulin, perform cell signalling, allowing cells in different parts of your body to communicate with each other. This is important for releasing hormones and fighting infections.
Method
A food diary was kept, in this case carried out in the form of a calorie tracker app, for a week. After the week's food intake had been recorded the information was then transferred to a questionnaire and some substitutions had to be made for food that had been consumed but was not an option on the questionnaire. Once all the information had been successfully transferred, a spread sheet was utilised to calculate the calorie content of the foods and for the protein, lipid and carbohydrate content of the food diary etc. to also be computed. Information from this spread sheet was used to analyse and discuss the subjects diet and to create graphs/charts to display certain data comparisons.
Results
Predictions
The subject had predicted that the largest portion of their dietary energy would come from carbohydrates followed by proteins and lastly fats, with no energy being gained from alcohol. The subject also predicted their average daily calorie intake would be 1800 calories and the top 3 sources of the major nutrients:
Carbohydrates
Pasta
Bread
Potato
Fats
Cheese
Sausages
Bacon
Proteins
Egg
Chicken
Ham
Results
When the results had been calculated it was seen that the subjects predictions had not been completely accurate, the actual percentage intake of protein and fat was higher than the Recommended Daily Allowance (RDA) whereas the predicted percentage intake of carbohydrates was lower than the RDA. In the actual percentage intake of nutrients, carbohydrates were still the highest calorie contributor but were followed by fats and the least energy actually came from proteins. The subject's daily calorie intake was lower than the predicted intake at 1345.5 kcal/d and the top 3 sources of the major nutrients were also different than predicted except for the fats.
Carbohydrates
Pasta
Chips
Cereal
Fats
Cheese
Sausages
Bacon
Proteins
Cheese
White fish
Milk
Data
The percentage of energy intake from the three main nutrients: carbohydrates, proteins and fats compared to the predicted percentage intake and the recommended daily allowance of energy intake of the three nutrients. The predictions for carbohydrates and protein were greater than that of the actual results whereas the prediction for fat was almost half of what the actual percentage intake was. Neither the predictions or the actual percentage of energy intake were equal to that of the recommended amounts.
The average calorie intake of the subject per day alongside the recommended daily calorie intake and the predicted calorie intake per day. The recommended intake for an average man is 2500 which is much greater than either the predicted or the actual calorie intake per day
The accumulated weight of each nutrient gained from their top 3 sources against the accumulated weight of each nutrient from their predicted top 3 sources. The predicted sets of both carbohydrates and proteins supplied much less of their respective nutrient than the actual top 3 sources did. However the top 3 sources of fat were the same as the predicted sources thus there is no difference.
The subjects daily calorie intake over a week. The intake increases slightly until the 10th of November at which the calorie intake drops significantly and rises again to similar levels as before.
Discussion
Should diet be changed/does subject want to change diet?
http://www.nhs.uk/Tools/Pages/HealthyEating.aspx
Comparison to another diet
This energy homeostasis system is more robust in some people than in others. In a fascinating experiment published in the journal Science in 1999, researchers overfed 16 non-obese young adults with an excess of 1,000 calories per day (beyond energy needs) for 8 weeks (10). They found an amazing 10-fold difference in fat gain between individuals, ranging from 0.4 to 4.2 kg of fat mass. Some people were able to burn off the excess calories without any increase in voluntary exercise*****, while others gained most of the excess calories as body fat. This suggests that the energy homeostasis system is more robust in some people than in others, and those who inherited a weak system are much more prone to fat gain. Keep in mind that this system doesn't have to defend against fat gain unless a person is overeating, so these individual differences are only relevant in the context of excess food intake. In 2012, I believe most people in affluent nations frequently overeat due to our unnatural food environment, and those who have a less robust homeostatic system gain fat over time as a result.
Prediction accuracy
Diet improvements
http://www.nhs.uk/Livewell/Goodfood/Pages/eat-less.aspx
Data collection method problems
Questions
Problems with self-reporting and how it affects results (see psychology book)
Other data collection methods - method is as good as the user makes it
Differences between what spreadsheet says about calorific content and what it actually is
Size of portions compared to what is on spreadsheet
Conclusion
Diet
Method
Factors - money - going home - sickness
Psychological Function
Food always gives us a feel of satiety or "satisfaction." A normal well-balanced individual human eats food for both physiological and psychological satisfaction. However, sometimes individuals' mis use food as they consider it a factor influencing their self-esteem and become victims of diet/food related conditions like anorexia or bulimia. Some individuals also go on "bingeing sprees" and lose control over their eating habits.
Social Function
From time immemorial food has been used to bring together people for celebrations as well as sad occasions. Food binds people together and no wedding/funeral is complete without the presence of food. It promotes a feeling of sharing and thus has a social function.
Being healthy and eating well is an amalgamation of all these essential functions of food.
Suggestions for improvement on diet e.g. lack of vit c, therefore eat more . . .
Social desirability bias
How could diet/method be improved.
