The movement toward raw food for weight loss has been growing steadily over the last several decades. Grounded in the idea that cooking actually robs foods of nutrients, as well as “acidifying” the body, raw food diets attempt to correct this deficiency. But does the science stand up to scrutiny?
Raw Food Weight Loss Diets
There are two basic principles behind raw food weight loss plans. These are:
- The process of cooking degrades the nutritional value of foods.
- Typical Western diets have an “acidifying” effect on the body, which can be reversed by eating raw foods, which are alkaline in nature.
A natural extension of the movement to buy organic, it seems intuitive that eating raw foods should be healthier than cooked foods. The logic goes that if eating organic foods is healthy, then those found in their natural (i.e. raw) state should be more stable, and cooking or further processing disturbs that delicate balance. Furthermore, it’s well known that many popular nutrients are destroyed by cooking, which further bolsters the argument in favor of raw food diets for weight loss. Its a well-known fact that vitamin C isn’t very stable to cooking, and the same goes for vitamin A. Similarly, water-soluble vitamins are frequently leached from foods during water soaks or boiling, which only strengthens the case against eating cooked foods. Unfortunately, as is so often the case with such arguments, the case is much more complicated that it originally appears.
A recent paper on calorie content of raw foods vs cooked foods explores the question of how cooking impacts the calorie content of food. The question of calorie content is usually studied at the point of consumption, rather than looked at from the perspective of cooking method. The question that should be asked should go something like: How does the the number of calories in broccoli differ if I eat that broccoli raw, as opposed to simply boiling it in water for 15-minutes. However, this gets at the heart of the raw food diet, because its hard to argue against the empirical evidence, which shows that people who follow a raw food regimen tend to lose weight. But are they losing weight because the diet is inherently healthier, or is it a function of simply calorie restriction?
With this singular fact in mind, perhaps it shouldn’t come as a surprise that researchers found a positive correlation between cooking and calorie content; meaning that generally speaking, cooking a food will increase the calories available to the consumer, when compared against the same foods, served raw.
Anthropologists have long-theorized that the human brain is the single differentiating factor between us, and our less advanced counterparts within the animal kingdom. But from the perspective of energy consumption, the brain is a pig, requiring vast amounts of energy relative to other processes. Observational research on other primates shows they spend far more of their time chewing their food, for the express purpose of breaking it down by mechanical means to extract the greatest number of calories possible. By contrast, humans harnessed fire, which greatly improves our capacity to extract the greatest number of calories from every bit of food we consume. We no longer have to sit and chew tubers for hours on end — we cook our food to reduce the workload on our dietary systems, then move on to other tasks.
With all of this as a backdrop, its hardly surprising that raw food dieters tend to lose weight. The simple expedient of “going raw” effectively restricts the calories available to the consumer. While its certainly true that some nutrients are lost during the process of cooking, most studies show that the net gain in nutrient-availability, dramatically overshadows the losses incurred during cooking.
While I suppose one could argue that, in today’s world, we consume far more calories than needed anyway, going raw also goes against my sensibilities, in that one ends up wasting a larger percentage of food, through digestive inefficiencies. For myself, raw seems to be a form of self-imposed calories restriction, which can be done without going raw. So for now, I’ll stick to the plan of keeping my overall calorie content low by modulating portion size and dietary choices, leaning toward reasonable portion sizes, lean cuts of meat, and vegetable-rich, well cooked foods.
Published November 2011.
- “Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements.” Donaldson MS. Annals of Nutrition and Metabolism, 2000; vol. 44, pp. 229-34. Abstract. Accessed November 2011.
- The Science Behind Raw Food. Accessed November 2011.
- “Cooking And Cognition: How Humans Got So Smart” LiveScience.com. Accessed November 2011.
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