Are 70 calories of fat from walnuts, coconut oil, cod liver oil, olive-oil, canola oil, the healthiest omega-3 IMHO, DHA, or macadamia oil or nuts etc. different in health effects: Yes, in important ways. Should you have 70 to 140 calories of fat 25 minutes before each meal? Yes – but keep reading.
All the aforementioned oils are beneficial to your health when sourced in specific ways and when used in specific ways:
(Full disclosure: I am a scientific advisor to a company that sells DHA and to the California Walnut Commission. Yes, I still believe omega-3 DHA, walnuts, macadamia nuts, and chia seeds are healthiest, but read on.)
Why have I been pondering this? It really started with The Dr. Oz Show with Montel Williams on as a guest. He was telling Dr. Oz about safflower oil, and how the way he was taking it would reduce your weight and, more importantly, your waist size. I questioned that – so as is the custom, back to the journals to separate myth from reality. The Cleveland Clinic Prescriptive Wellness Committee’s conclusion is that all these fats provide health benefits; this committee is the one that judges and votes on what products become available on the Cleveland Clinic Wellness site and at the facilities’ stores.
When sourced properly and used first thing in the morning, there is strong scientific evidence (randomized controlled double blind studies, in many cases) that show all these oils (or in the case of walnuts, the nuts with these oils) decrease appetite; promote weight and waist loss (if they result in a sustained decrease in appetite); decrease LDL (the lousy) cholesterol; decrease age- and health- robbing triglyceride levels; and increase healthy HDL cholesterol. (There are some key points for science to unveil yet, like what happens to LDL and HDL particle size and activity, but that data is not available just yet.)
Long-term studies, more than 6 weeks and certainly more than 20 weeks, are needed to rule out adverse effects of some of these fats taken in this way on cancer promotion etc. (We do have long-term data on walnuts and omega-3 DHA that these decrease cancer risks – the other oils may not, or may increase risks greater than the beneficial decrease in heart and vascular disease and preservation of memory that we believe is likely.) Another reminder, the cancer benefits, long-term preservation of memory benefits, and the actual decrease in heart disease benefits have only been shown in humans in studies we reviewed for olive oil, walnuts and omega-3 DHA and fish oils – these oils also decrease inflammation. My best estimate, and that of the CC committee, were that two tablespoons of these oils first thing in the morning and at the start of every meal works; all data look similar for weight and waist loss and appetite control using oils and non-cooked foods with these oils in this way, whether safflower, coconut, walnut, fish, olive or macadamia oil.
While the conclusions above are from the committee’s discussions and deliberations, below is my extra take on the data and reasons why this works, much from animal studies on mechanisms, and presented in our (Dr.Oz and my) book, YOU: On a Diet. But here is the (very) short form (no need to get your hands on the book – only do that if you want the recipes, more mechanisms, tricks, and ways to lose by dieting smart, not hard): A little fat (70 to 140 calories worth) before a meal stimulates release of the hormone cholycystokinin (and other effects) from your early intestinal wall, stimulating your vagus nerve to decrease stomach emptying (so your stomach stays more full, so you feel full), and telling the satiety center in your brain that you are no longer hungry (that brain effect takes about 25 minutes after fat arrives in your empty stomach). Consuming healthy fats first in a meal (even better if it’s 25 minutes before) inhibits your appetite in two ways, promoting weight and waist loss, which in turn helps control blood sugar, blood fats and blood pressure, and should have long-term beneficial health effects.
Some of the oils in animal and human models, when consumed with food or when heated, increase inflammation and turn on genes that promote cancer. Do they have the same effect when the fat is consumed first? We just don’t know or have thorough-enough human studies to determine that. That’s why we promote walnut, olive and fish oils, especially omega-3 DHA, in the book as the fats to have first – there are data for those specific fats showing reduction in inflammation and long-term health benefits.
Since I’m data driven, I personally choose oils that we know have other long-term beneficial health effects like omega-3 DHA and walnut.
See, Montel, he was right.