Comparison of Popular Diets: a Community-Based Diet Club, an Intermittent Fasting Diet and Atkins Diet
This article will be exploring three different diet types for obese patients between the ages of 19 and 64, to try and gain a better understanding of some of the more popular diets, how they work and if this patient group would benefit from these diet types. I chose this age group as it includes most of the adult population and the nutritional guidelines are written in age categories and this is one age category. The diets that are being compared are a community-based diet club, an intermittent fasting diet, and the Atkins diet. I chose to compare these diets as they are three popular diets which have been well established and around for several years furthermore, they all take a slightly different approach to weight loss. The diets work fundamentally by controlling what foods can and cannot be eaten to promote weight loss. However, there is more to a diet than losing weight. For each diet, I will be answering the following questions that I believe will help to create a better understanding of each diet. The questions are: What are the fundamental principles of the diet? Are you able to stick to the recommended nutritional values? Does it follow the NICE guidelines? Is there evidence for successful weight loss in both the short and long-term? What are the positives and negatives? Any additional evidence information?
Guidelines
The NICE guidelines for a diet suggest that the diet website or club needs to be a place which has safe advice and should also include information about exercise to accompany the diet. Furthermore, the weekly weight loss should not exceed 1Kg.
The government nutritional guidelines for an adult between the ages of 19 and 64 are the following: calories per day 2500 Kcal for men and 2000 Kcal for women. Carbohydrates per day 333g at least for men and 267g at least for women. Protein per day is 55.5g for men and 45.0g for women. Fats per day 97g for men and 78g for women. Saturated fats per day 31 for men and 24 for women.2 Fruit and Vegetables per day 5 portions (80g) for both men and women.
A community-based diet club
The example of a community-based diet club (CBDC) consists of splitting foods into two main categories ‘free’ foods and ‘syn’ foods. The main principle is there is no restriction on the number of free foods that can be eaten in a day however, there should be a maximum of 15 syn foods a day. Free foods include fish, lean meats, fruits, and vegetables if they are not cooked in oils as well as pasta and eggs. Syn foods are food that has a high fat or salt content including crisps and chocolate. The diet works by eating healthier options and in a calorie deficit to lose weight. The CBDC has weekly meetings where members have a weigh-in and they discuss their progress so far.
Having fruit and vegetables in the free food category promotes and allows for the consumption of five portions of fruit and vegetables a day and allows members to be able to stick to the government guidelines. To add to this in a review of this CBDC they found that the average CBDC member had 6.2 portions of fruit and vegetables a day, this meets and exceeds government guidelines (five portions of fruit and vegetables a day). This review also found out that members were able to stick to government guidelines from an example meal plan from the official website the protein intake was 103g which exceeds the government guidelines. However, the average calories participants consumed per day were 1538 this is lower than the calorie recommendations. Furthermore, this is from the example meal plan and participants may not actually stick to the meal plan.
In terms of successful weight loss, a study found that at 12 weeks there was an average of 5.4Kg weight loss, this complies with the NICE guidelines as it is 0.45Kg of weight loss per week. At 24 weeks an average of 11.1Kg weight loss also complies with the NICE guidelines as it is a total weight loss of 0.46Kg per week.6 It also shows how there is evidence for weight loss across several weeks.
However, it must also be noted that there is little to no evidence of weight loss for a long time period (longer than one year) so it cannot be assumed that the trend of 0.45Kg weight loss per week continues and whether members gain weight after leaving the program. Also, both studies have a small number of participants.
CBDC does not provide much evidence to its members about calories and portion sizes. This means that members could not lose weight if they are not in a calorie deficit.
Overall, the CBDC sticks to NICE and most of the government guidelines apart from the calorie intake. The diet also has strong evidence for weight loss. However, the participant number is low and there is no evidence for longer-term weight loss. Also, members may not be able to get to a group if they live in rural areas.
Intermittent fasting
Intermittent fasting is the second type of diet. Intermittent fasting works by having a set number of days of the week where you eat with no restrictions and then fast for the other days.
Alternate day fasting (ADF) is a type of intermittent fasting it is where you have one day of no restrictions on eating and one day of fasting which consists of eating limited calories. During the fasting days, men can consume up to 600 calories and women 500 calories.9 This is about one-quarter of daily calorie requirements which does not comply with the nutritional guidelines.
There is evidence for short-term weight loss one study's 10-week trial consisting of 20 obese individuals on the ADF diet found when on the ADF diet there was a 0.68Kg weight loss average per week. This complies with the NICE guidelines as it is less than 1Kg loss per week.
In terms of being able to stick to Nutritional guidelines, in a study with 74 participants for ten weeks, two weeks baseline, and eight weeks on an ADF diet the meals the participants ate during the fasting days did not adhere to the guidance. For example, on all three of the fasting days, the number of calories consumed was 500Kcal and between the three fasting days the average amount of protein they ate was 21.7g per day, the Nutritional guidelines state that it should be 45.5g for women and 55g for men. Furthermore, the average amount of carbohydrates consumed was 74.3g.
However, there is limited evidence for long-term weight loss.
Overall, there is evidence that shows weight loss is present short-term, however, the study size was small and was completed eleven years ago. To add to this there is limited evidence for long-term weight loss. During fasting days, the restriction on calories and an example meal plan for fasting days go against the government's guidelines. The diet does, however, have a lot of freedom allowing patients to eat their normal diet 50% of the time, and the other 50% have reduced calories but no foods are banned or restricted. Also, giving patients the ability to calorie count means that they know they are eating in a calorie deficit and can stick to eating in a calorie deficit.
The Atkins diet
The Atkins diet is based on having low carbohydrate intake and a high protein and fat intake. The diet is based around the idea that by eating low levels of carbohydrates and high levels of fat and protein it promotes ketosis.
The diet is split into four phases, the phases slowly incorporate more carbohydrates into the diet. Phase one allows for 20-25g of carbohydrates daily, it allows for the consumption of nuts, seeds, some vegetables, proteins, and healthy fats. Phase two allows 25-50g of carbohydrates daily, it allows for the consumption of the same as phase one and certain fruits including cherries, whole milk, Greek yogurt, different beans, and tomato juice. Phase three allows 50-80g of carbohydrates daily and allows for the same as phase two and starchy vegetables such as carrots and whole grains. Phase four allows for 80-100g of carbohydrates and allows the same foods as stage three.13The diet does not comply with the government guidelines surrounding carbohydrate daily intake during any of the stages. Even during stage four, it is only around one-third of the recommended intake.
The restriction of some of these foods especially the fruit and vegetables could lead to a diet that is missing certain vitamins for example vitamin A, which is found in carrots and carrots is not allowed until Phase three, and vitamin B1 which is found in milk and milk is restricted until phase 2, this could lead to a deficiency in those vitamins.14,15Also, not heavily controlling the fat intake could lead to overconsumption of saturated fats.14 This could potentially be overcome by education and educating the participants about the importance of including certain foods that are high in those vitamins.
The official Atkins diet website does not seem to have any information regarding exercise and exercise plans. This goes against the NICE guidelines.
The diet has evidence that there is immediate weight loss. A study that included 63 obese men and women found that participants lost weight in the first 3 and 6 months of the diet and at 6 months having the greatest difference in weight loss however, after a year they found that there was no significant difference in weight loss. This shows how the diet has immediate weight loss but no evidence that suggests that the diet works longer than 6 months.
The diet requires you to count the calories of the carbohydrates which could be difficult however, to overcome this the official website has a calorie counter to make it easier.
Overall, the Atkins diet does have evidence that it works from multiple studies and has a large, short-term weight loss, however, there is only evidence for weight loss up to 6 months and no longer-term weight loss studies. It also goes against NICE and government guidelines and if the patients are not properly informed it could lead to potential deficiencies in certain vitamins.
Conclusions
It should be noted that the three diets discussed are not the only weight loss options and there are diets and other weight loss methods that I did not mention for example the Paleo diet, exercise only, and bariatric surgery.18 These are alternatives to the three diets mentioned and they could be more suitable depending on the patient and their lifestyle and goals.
Overall, each diet has its strengths and weaknesses, and no one diet is best for every patient. However, it must be said that the CBDC diet complies more with the NICE and government guidelines compared to the ADF and the Atkins diet. However, none of the diets have evidence that weight loss either continues or if members put on weight once, they have stopped the diet. Also, none of the diets have long-term weight loss studies and evidence also none of the diets include information about exercising and exercise plans. I think it should also be noted that the diet a patient chooses to be on may reflect what works for best for their lifestyle for CBDC it requires transport to weekly meetings and a community aspect whereas, the other two diets are more personal, and the patient does not need to travel to get to the meeting.
