On his show last week, Dr. Oz said he "implicitly" trusts Rovenia Brock, a nutritionist with a PhD from Howard University. He made these comments in response to Dr. Brock's statement that it was okay to consume a sweet for breakfast in order to lose weight. She claimed she based her statement on studies that supported her. In fact, she offered a donut as an example of a sweet that could be consumed and Dr. Oz said he trusted her judgment. (Let's not forget this is the same Dr. Oz who says people should eat regular ice cream. See my previous blog on the topic.)
Before we tackle the question of which study or studies, if any, support this statement, let's analyze the substance of donuts for a moment. Donuts come in different shapes, sizes, and flavors. There are glazed donuts, cream filled donuts, sugar-coated donuts, etc. Donuts are often fried. Most donuts have somewhere between 200 and 400 calories with fat often comprising half of the calories. Dr. Brock made no distinction between the type of donut she was recommending and Dr. Oz asked for no clarification. He simply stated he trusted her.
Now let's look at the science. In the journal Steroids, a paper was published based on research done in Israel that included 193 obese (BMI 32.2±1.0kg/m(2)), sedentary non diabetic adult men and women (47±7years) who were randomized to a low carbohydrate breakfast (LCb) or an isocaloric diet with high carbohydrate and protein breakfast (HCPb). (To read about the study, cut and paste this url: http://www.ncbi.nlm.nih.gov/pubmed/22178258 Meal timing and composition influence ghrelin levels, appetite scores and weight loss maintenance in overweight and obese adults.)
During the study, both groups of subjects consumed the same amount of total daily calories, except one group consumed more calories during breakfast than during other meals. These calories came from both proteins and carbohydrates. This loading of mixed calories to breakfast resulted in subsequent greater weight loss than those who balanced out calories during the day.
Carbohydrates come in several forms. There are simple and complex carbohydrates and there is soluble and insoluble fiber. A whole grain cereal can be high in both carbohydrates and fiber. Fiber can be expected to increase a sense of fullness. In fact, a previous study showed that consuming cereal for breakfast results in greater net weight loss. (To read about the study, cut and paste this url: http://www.ncbi.nlm.nih.gov/pubmed/16339127 Dietary intake of whole and refined grain breakfast cereals and weight gain in men.)
So the question is how did Dr. Brock and Dr. Oz make the leap from the Israeli study (which is the only study available to show such results) to declaring on national television that it is okay to consume a donut for breakfast if you want to lose weight.
By the way, at no time did he or she add that doing so required less calorie consumption later in the day. Rather, they implied that doing so would result in less calorie consumption during the day, a fact not supported by the study that required specific adherence to a strict calorie count. The study did show that a larger breakfast with protein and carbohydrates increased satiety for the rest of the day. Wow, imagine that. Eating a big breakfast may make you less hungry later in the day. Where's the news in that? Nevertheless, the study never said you should use fatty donuts as a source of your carbohydrates, so don't.
Furthermore, the researchers did not study what results would be obtained if the breakfast only included protein without carbohydrate. A recent study done in England and published in the European Journal of Nutrition showed that, in fact, consuming protein for breakfast offered more satiety than carbohydrates (in the form of a croissant and orange juice), with ingesting the protein alone resulting in lower subsequent calorie consumption during lunch and dinner. (To read about the study, cut and paste this url: http://www.ncbi.nlm.nih.gov/pubmed/22948783 Variation in the effects of three different breakfast meals on subjective satiety and subsequent intake of energy at lunch and evening meal.)
So why did Dr. Brock and Dr. Oz use donuts as an example. In my opinion, it's TV ratings, pure and simply. If they had said you should eat more whole grain cereal as a source of carbohydrate, no one would notice. But say you can eat a donut for breakfast to lose weight and that becomes newsworthy and sensationalistic; people take note.
One can only wonder how many Dr. Oz disciples hastened to follow the show's advice and will now add a donut to their breakfast routine. Poor, misguided souls.
So to answer the question posed in the title, should you trust Dr. Oz and Dr. Brock, I say no. You cannot trust their advice on donuts, and once you can't trust one thing they say, you make the decision regarding what you can trust.
If you want to include carbohydrates in your breakfast meal and want to satisfy your sweet tooth, then include a naturally sweetened, healthy, non-preservative muesli and leave the donuts to mortals foolish enough to take advice from doctors who have sold out to celebrity and TV ratings.