The American population is fat. What’s worse, we are getting fatter. For many years, a body mass index (BMI) of 27 or more (weight in kilograms divided by height in meters squared) was the standard criteria for being overweight, and a BMI of 30 or more was the criteria for obesity. This meant that more than one third of U.S. adults were overweight. In recent years the criteria has been reduced to a BMI of 25 or more to be considered overweight, with the obesity criteria remaining the same. Now, more than 50% of U.S. adults are classified as being overweight. Interestingly, as the number of overweight individuals skyrockets, so too does the number of various diets that Americans are willing to try in their search for the thin standard that our culture idolizes. One of the most popular, and many claim successful, of the conglomerate of diets is the Atkins protein diet, named after its founder and guru Dr. Robert C. Atkins. With more than six million copies in print, Dr. Atkins’s New Diet Revolution proclaims to be “the amazing no-hunger weight-loss plan that has helped millions lose weight and keep it off” (Atkins). Sounds great, but what is this diet, and is it too good to be true?
How does the diet work?
The purpose of the Atkins diet is to change one’s metabolism and lose weight easily by eating foods high in protein and limiting foods high in carbohydrates, which tend to raise blood sugar levels the most. The diet works on the principle of ketosis the process by which excess, stored body fat (the body’s secondary energy source) is burned, resulting in weight loss. A background understanding of the body’s natural energy system helps to understand Atkins rationale. Diets high in carbohydrates increase your body’s production of insulin because of their glucose and sugar makeup. When insulin is at high levels in the body, the food you eat can readily get converted into body fat, in the form of triglycerides. Thus, if lower amounts of carbohydrates are consumed, the body naturally produces less insulin and looks to other sources for fuel, namely FAT! For this reason, the Atkins diet restricts processed and refined carbohydrates and limits intake to 15-60 grams per day, encouraging protein and fat consumption. When the body lacks its primary energy source (carbohydrates) it will naturally turn to its next source (fat) to burn for energy. When the body breaks down fat, ketones are formed and the appetite is naturally suppressed. One reaches ketosis when his or her carbohydrate intake is less than 40 grams per day. The average person not on this diet consumes 300+ grams of carbohydrates per day.
In addition to changing one’s metabolism through the process of ketosis, the Atkins diet also claims to work because of the diet’s success in reducing food cravings by allowing the dieter to eat more nutritious, flavorsome foods than low-fat diets, so the body will be satisfied sooner. The diet leaves you less hungry than high carbohydrate diets, so you eat less and you stay satisfied longer. This aspect of the diet address what Dr. Atkins refers to as the “biggest battle that most people have with weight loss” the constant obsession with food. Cutting carbohydrates levels blood sugar levels throughout the day, eliminating false hunger pains and reducing cravings for cheat food
What can you eat on the diet?
The Atkins diet is set up in four phases, gradually incorporating more carbohydrates into your diet as you successfully complete each stage. The first phase is what Atkins is best known for, the initial fourteen-day Induction diet. Dr. Atkins New Diet Revolution book states that the purpose of the Induction diet is “to correct, as expeditiously as possible, an unbalanced metabolism.” During this phase, your body will switch from a carbohydrate-burning to a fat-burning metabolism; it will stabilize your blood sugar, stop cravings through abstinence (not moderation), and break addictive eating patterns. The rules of this diet are strict, with every carbohydrate going into your mouth being counted, including the oft forgotten grams in chewing gum, cough syrups, and cough drops. Intake is restricted to 20 grams of carbohydrates a day at most, and if a certain food is not on your Induction diet, you are to have absolutely NONE of it. In this stage no fruit, bread, grains, starchy vegetables, or dairy products other than cheese, cream, or butter are allowed. A weight loss of 5 pounds or more a week is not unusual in this stage. In the following 3 stages, Ongoing weight loss stage, Pre-maintenance stage, and Maintenance stage, more carbohydrates are slowly added into the diet and more deviations are allowed from the original “no-no” list. The goal of the final stage,Maintenance, is to teach the dieter what level of carbohydrate consumption he or she can manage without weight gain.
Will the diet really work?
If one follows these rules and sticks to a low carbohydrate, high protein diet, Atkins claims that you will recondition your body to burn fat efficiently, and thus lose weight, and you will never go hungry again. You can eat all the rich, fatty foods you want and still lose weight. In fact, Atkins states that “most people will lose 10-30 pounds in the first month”. Based on surveys conducted by the Atkins Diet Center, this diet appears to be more effective than low-fat diets in enabling people to lose weight. 54% of Atkins dieters say their loss has either met or exceeded their expectations, and fewer Atkins users still weigh in as border line obese or obese (47% versus 58% of low-fat diet followers). In addition, 44% of Atkins dieters rated the diet favorable on controlling cravings, as compared to 21% of low-fat dieters who found their diet favorable in controlling cravings. Likewise, 58% of Atkins dieters rated their diet favorably on maintaining energy levels versus 31% for low-fat dieters.
As if this diet couldn’t seemingly get any better, there are also additional benefits to the Atkins diet, besides weight loss. Atkins claims that your overall health will improve on the diet and you will feel better as you burn stored fat and clean our your body. Fatigue, irritability, depression, headaches, and joint and muscular pain simply go away and you may even experience significant improvement in your cholesterol level and blood pressure . On the Atkins diet you will also sleep better, as excess carbohydrates are responsible for the excess insulin which drops the blood sugar level too low and triggers the cortisol response. Rather, the amino acids in the high protein diet increase dopamine receptors in the brain, so you feel good for a night’s rest.
What do the experts say about the Atkins diet?
Although there are countless testimonials of the effectiveness of Atkins protein diet, and although surveys conducted by the Atkins Center point to the diet’s success, numerous health organizations and medical professionals have sharply criticized the Atkins diet, both for what it does to the body and for what it does not do for the body. In an article in the journal Clinics in Sports Medicine, Dr. Rosemary E. Riley summarizes what many doctors agree are some of the dangers of low carbohydrate diets such as the Atkins diet, or the “protein-sparing modified fast” as it is often referred to in the medical realm. 300 grams is the recommended amount of carbohydrates that an adult should consume on a daily basis, according to nutritional professionals. The Atkins diet, which promotes carbohydrate consumption as low as 20 grams, does not allow you to consume the fiber and photonutrients contained in fruits, vegetables, and whole grains that are necessary for healthy living. Riley also points out that low carbohydrate diets cannot maintain the glycogen stores for high-energy activities such as long distance running and extensive weight lifting. This ketotic diet may also play havoc with medications and other treatments for obesity. The diuretic effect that the diet has on the body may necessitate that high blood pressure medicine be adjusted. Fat intake is another area that Riley believes the Atkins diet may deviate from what is healthy. Foods that are high in protein such as meat, eggs, and cheese are also high in saturated fat, which we now know will increase blood cholesterol levels if eaten in excess. The American Heart Association sets a limit that only 30% of one’s daily calories should come from fat, yet in the Atkins diet one can eat as much fat as desired.
In recent years the American Dietetic Association has become concerned with the increasing amount of misinformation on food and nutrition circulating in the U.S. The Association released a paper to inform and guide the segment of the population who may be victims of consumer misinformation. Much of this information is blatantly in contrast to the methods of weight loss heralded by Dr. Atkins. First of all, Atkins claims that it is normal and even desirable that in theInduction phase of the diet the individual loses 5 pounds or more the first week. The American Dietetic Association, however, maintains that in order to avoid potential health hazards one should only lose 1-2 pounds per week. Pounds lost quickly on diets like Atkins are often regained because faulty habits have not been changed. Another area where the American Dietetic Association disagrees with Atkins is with fat intake, as Riley pointed out. Low carbohydrate ketogenic diets are often high in fat, which may increase cholesterol and lead to many other health risks.
The research concerning the effectiveness of protein versus carbohydrate rich meals in curbing cravings is quite mixed. In a 1990 International Journal of Obesity article, Barkeling, Rossner, and Bjorvell reviewed five studies comparing the effects on satiety of meals with different proportions of protein and carbohydrates and found that three studies confirmed Atkins theory that a high protein meal will curb cravings. Two studies did not find any differences in food intake of a subsequent meal or feelings of fullness after a high protein meal compared with a high carbohydrate meal. In response to these contrasting results, Barkeling, Rossner, and Bjorvell designed their own study with the aim to “investigate whether a high-protein lunch meal has a different effect on satiety than a high-carbohydrate lunch meal by measuring the intake of a subsequent ad libitum evening meal intake and the subjective feelings of motivation to eat” (Barkeling, Rossner, and Bjorvell).
The subjects of this experiment were twenty healthy women aged 21 to 47 years who were of normal weight for height. The two lunch meals were of equal caloric and fat content and of similar fiber content. The high-protein meal consisted of a meat casserole with whole meal spaghetti and the high carbohydrate meal consisted of a vegetable casserole with ordinary spaghetti. At lunchtime the subjects arrived at the laboratory and were given either the high-protein or the high-carbohydrate meal with a glass of water and were asked to eat the whole portion of food and to drink all the water. They were not allowed to eat anything between the lunch and evening meal. At dinner, the subjects were served a standardized evening meal in excess and were asked to eat until pleasantly full. Results of the study revealed that at the evening meal subjects ate 12% less after the high-protein meal when compared to the high-carbohydrate meal. The results of this study indicate that a high-protein meal gives a more sustained satiety than a high-carbohydrate meal. While this basic finding does in fact support the Atkins diet, Barkeling, Rossner, and Bjorvell indicate at the close of their report that they are in no way recommending obese subjects to choose high-protein meals in favor of high-carbohydrate meals. They acknowledge shortcomings of their study, including the fact that they only investigated the short-term effects of protein and carbohydrates on satiety. Secondly, high-carbohydrate diets also have a naturally higher fiber content than high-protein diets because high-carbohydrate foods such as fruit, vegetables, cereals, and grains are rich in fiber, which has a positive effect on satiety. Thus, it is not easy to determine whether in practice a high-protein diet or a high-carbohydrate diet gives more satiety than the other.
In a 1999 article in Appetite, Yale University researchers Latner and Schwartz reviewed 11 studies on the effect of high versus low carbohydrate diets on satiety and motivation to eat. Of these studies, 8 support Atkins’ claim that a low-carbohydrate, high-protein diet will lead to reduced hunger. Latner and Schwartz point out that of the 3 studies that found little difference between the effects of protein and carbohydrate upon intake, the studies deliberately used foods of different sensory qualities and water content in addition to macronutrient composition. Thus, differences in later food intake could be due to any of these factors. To examine this question, Latner and Schwartz designed a study in which 12 female Yale University students were offered three liquid test meals at midday on separate occasions — one high in protein, a second high in carbohydrates and a third solution containing half of each of the others. All lunches contained 450 calories and were served in liquid form, with uniform appearance. At dinnertime the subjects were given a buffet-style dinner in isolation and instructed to eat as much or as little as they liked. Subjects were then given a questionnaire and their food intake was calculated. A result from this study revealed that intake at dinner was lower after the protein lunch than after the carbohydrate lunch. Subjects also consumed less after the mixture meal than after the carbohydrate meal. Latner and Schwartz conclude that these results demonstrate that the macronutrient composition of a midday meal affects both intake at dinner and self reported measures of hunger, enjoyment and excitement about eating. The ingestion of high protein foods can lead to an increase in satiety and to lower food intake at an evening meal than an equally caloric high-carbohydrate lunch.
In a similar study at the Rowett Research Institute’ Human Nutrition Unit, researchers studied 16 normal-weight men to determine the effect of a high-protein, high-carbohydrate, high-fat, or an equal mixture of nutrients breakfast on the amount of food eaten at lunch. Each treatment was equal in calories and in density. Whereas other studies used female subjects and the lunch to dinner eating schedule, this study looked at men and the breakfast to lunch eating schedule. Despite these changing variables, the results of the study echo the countless other studies. The subjects were significantly less hungry before lunch on the high-protein and mixture (33% protein) treatments. At lunch, they ate more calories after the high fat treatment than after any of the other treatments. Again, Atkins proclamation that a high protein meal will curb appetite so as an individual naturally eats less appears to ring true.
Despite the large number of studies that indicate the Atkins diet is effective at curbing appetite, a study published in the May 6, 1999 Addictive Behaviors journal indicates some discrepancy in this topic. The study by Gendall, Joyce, and Abbott investigated the effects of meals differing in macronutrient composition on subsequent food craving, bingeing, nutrient intake, and mood. Nine women were recruited for the study, and they received one each of a high-protein, high-carbohydrate, and mixed meal on three separate days. Appetite and mood ratings were taken before and at four intervals after the meal. While pre-meal hunger, appetite, and mood ratings were similar across meal type, after the protein-rich meal, craving for sweet carbohydrate-rich foods was significantly higher than after the carbohydrate and mixed meals. It is necessary to note, however, that this study consisted of nine women recruited by advertisement who met stringent criteria for craving and had prospectively recorded a craving frequency of at least once per week over a two month period. The findings of this study suggest that consumption of a protein-rich meal increases susceptibility to craving sweet-tasting, palatable foods in vulnerable women. Thus, these results must be examined in light of the subjects, noting that many dieters who go on high-protein diets such as Atkins may not qualify as this classification individuals and therefore may not face these particular cravings.
A 1985 study published in The American Journal of Clinical Nutrition by Dr. James C. Rose of the University of Vermont and R. Ethan A.H. Sims also calls into question Atkins philosophy of a low-carbohydrate diet decreasing appetite. In this study, a group of obese patients went on a low-carbohydrate diet and then a high-carbohydrate diet and another group of obese patients had the diets in the reverse order. The researchers found that “the initial two weeks of dieting was associated with a decrease in appetite and elevation of psychological well-being, regardless of the composition of the diet” (Kolata). Therefore, changes in appetite and psychological reactions to dieting did not vary with the type of diet.