Two unusual diets that led to weight loss and the improvement of metabolic profiles have been in the news lately. In an earlier draft of this paragraph, I was harsh in calling out both dieters – a science teacher and a nutrition professor. I felt and still feel that they should be mindful of their positions of influence and temper their enthusiasm for diets that are probably unhealthy and suspiciously fad-like. In addition, both men offer simplistic explanations for obesity and unrealistic advice for groups they appear to be judging.
In the first example, a high school science teacher, John Cisna, eats meals from McDonald’s for 90 days, loses weight, and improves his metabolic profile (i.e., his blood fat and cholesterol levels). Mr. Cisna refers to his self-imposed diet as an experiment and determines that the choices people make, not the food sold at McDonalds, makes them fat.
Mr. Cisna is correct; our choices have everything to do with our outcomes. He is incorrect in assuming that everyone has the same choices available to them. In his pseudo experiment (more on that in a moment), he had his students choose his daily meals within certain parameters. The parameters were that he consume 2000 calories a day and stay within the recommended daily allowances of certain macronutrients (e.g., total and saturated fat). The local McDonald’s franchise covered the cost of the meals. In news stories about his 90 day diet, Mr. Cisna points out that he had to be smart about what he was doing. If he ate a high fat breakfast, he would have to choose a lower fat lunch or dinner in order to stay within his parameters. This is exactly what the Dietary Guidelines for Americans tell us to do, and what so many of us have trouble doing. Mr. Cisna is an educated man with above average numeracy who had 3 people watching the numbers with him. He was also able to make choices among all price ranges. In some of Mr. Cisna’s interviews, he suggests that people who blame McDonalds for their obesity lack self-control. I do not expect, nor should he, that the average McDonald’s customer has his same math skills or assistants to help them track their calories. And tracking calories and other macronutrient amounts IS important. We already know from scientific study that fast food and sit down restaurants generally serve foods that contain at least a half a day’s worth of calories, fat, sugar and salt. People who obtain most or all of their meals from fast food and sit down restaurants, especially in the absence of nutrition labeling – and math skill - are at great risk for consuming a diet that is harmful to their health.
In addition to controlling his calories, which he did not do before the McDonald’s diet, he also began exercising for 45 minutes a day.
Mr. Cisna’s diet plan was not an experiment and we cannot make causal inferences from his personal results. An experiment by definition requires multiple subjects randomized into treatment conditions, including one in which nothing changes. In most situations, if a person reduces their caloric intake and increases their exercise they will begin to lose weight and this initial weight loss will improve their metabolic profile, especially if they are following the recommended nutritional guidelines. Because Mr. Cisna’s 90-day diet was not in any way an experiment, I am left with a few questions: What would happen if he did this for 90 more days? What if he ate at McDonald’s but did not have the nutrition information available to help him stay within his parameters? What if he had very little money with which to purchase the food? What would happen if a woman followed his exact plan? Or a younger person or an older person or a person of a different ethnicity? What if he did this for 6 mos. or a year or for his whole life, as some seem pressured to do?
In the second example, a nutrition professor, Dr. Mark Haub, eats Twinkies, etc., for 10 weeks, loses weight and improves his metabolic profile. He refers to his diet as a class project stemming from his teachings in nutrition. I am just aghast by this, but as I researched him a little further, I saw that his doctorate is not in nutrition; it is in exercise science/physiology. Dr. Haub has also been vocal about his results and suggests that the convenience store diet – something people living in food deserts might be forced into – are not necessarily bad and will not lead to obesity– as long as one makes the right choices.
I feel that Dr. Haub’s extrapolations are out of place and far too simplistic. It feels like an example of an over educated, privileged person suggesting he knows what an ‘other’ less privileged person is experiencing.
He claims that his convenience store diet, which for him meant that 2/3 of his calories came from snack foods, caused his weight loss and improved his metabolic profile. Like Mr. Cisna, Haub did not conduct an experiment and headlines misrepresent what he actually did.
Professor Haub consumed a lot of sugary, processed snacks similar to and including Twinkies, but he also ate some vegetables, took a multivitamin and drank protein shakes. In addition, and this is huge, he reduced the amount of calories that he consumed - from 2600 to 1800.
I have the same concerns and questions about this diet as I did the McDonald’s one. I suspect that the reason for Dr. Haub’s weight loss is that he reduced his intake by 800 calories. (He has told reporters that he monitored this closely by writing down everything he ate.) I further suspect - and evidence supports - that over time, a diet high in processed, sugary cakes will lead to metabolic irregularities and poor health. Lastly, and most importantly, he made a statement to one reporter that he wanted to be able to say that the diet was unhealthy, but the “data doesn’t support that.” The data do not support anything… it was not an experiment or a quasi-experiment. It was not research – there are no ‘data’.
Both Dr. Haub and Mr. Cisna put themselves on a diet to lose weight. During the time that they were on the diets, counting calories and exercising, they lost about 30 pounds each. This weight loss may have triggered improvement in their metabolic profiles as well – this is an assumption because we do not have a counter-factual or comparison group. It makes sense that the weight loss did cause the improvement. It does not make sense to suggest that a long-term diet of processed foods high in sugar or fried foods high in fat and sodium is health promoting. Science already tells us that there are adverse consequences to this kind of diet pattern. Both men’s claims as presented in the media are misleading. Cisna did not eat McDonalds without careful attention to calories and the macro-nutrient content of his meals, his choices were not limited by cost and he significantly increased his exercise. Dr. Haub’s diet included vegetables, protein shakes and vitamins; this is not similar to a diet consumed by someone who has limited income and has to eat most of their meals from a convenience store.
In my opinion, the headlines and the diets they report are pure sensationalism. Please, choose your calories from foods with health promoting properties, like those recommended by the Nutrition Source at Harvard.