Building a healthy eating plan requires that you consider three things. What are they? Read on to learn what they are and what you should do.
Building a healthy eating plan requires that you consider these three things.
How much to eat
What to eat
When to eat
Up until the last decade, most nutrition science was focused on the first two.
How Much to Eat
In looking for the culprit for weight gain and disease, the amount of food we eat was an obvious first contender and that's where scientists started in the early 20th century. Eat more and you gain weight, eat less and you lose or at least not gain. Simple enough. This is where the notion "a calorie is a calorie" comes from. Generally speaking, it is true, but by itself, incomplete. This is also where all the studies originated that explore the effects of caloric restriction (CR) on longevity.
What to Eat
Second place scientists looked at was the balance of nutrients in our food. The impact on health that the balance of nutrients had was easy enough to measure in rat experiments. Feed groups of genetically identical mice two different diets, for example, one that is balanced in carbohydrates, proteins and fats and one that is high in carbs and fats and low in protein and the results are very straightforward and easy to replicate. This is the juncture where we started seeing dietary theories pop up and take hold. Low carb, ketogenic, paleo, Atkins, vegan, vegetarian, whole30, fruitarian, nutritarian, grain-free, gluten-free, dairy-free, and lectin-free, are all theories that maintain that a higher or lower amount of a particular group of nutrients (macro or micro) in your diet is better for you. We all need all macronutrients and all micronutrients in our diet and claiming any particular diet to be universally healthy for everyone at all times is misguided. Age, gender, current health status, different health conditions, pregnancy status, whether you are an athlete, etc. all impact us and may require a slightly different balance of nutrients at different stages of life. This is not to say there are no hard and fast rules. There are and they are as follows:
Any food that causes your insulin levels to spike should be consumed infrequently and in small quantities. It is a spectrum, but the more refined a carbohydrate, the worse the spike in your insulin when you consume it. This is because processing removes the fiber from the food and without fiber slowing down digestion, the food is digested and glucose levels and in turn insulin levels spike in the blood in a matter of minutes. (Takeaway: The less processed your food, the better!)
Any food that has been grown/prepared with the use of pesticides, herbicides, added hormones and/or synthetic chemicals (such as artificial flavorings and colorings) have the potential to cause DNA mutations and act as a carcinogen in your body. (Takeaway: Try to eat organic as much as possible. If you cannot buy everything organic, google "dirty dozen" and try to buy at least those foods organic and wash the rest really well.)
Unsaturated fats (fats that are liquid at room temperature - mostly plant fats with the exception of fish and krill) are anti-inflammatory and saturated fats (fats that are solid at room temperature - mostly animal fats with the exception of coconut oil and palm oil) are inflammatory, but this does not mean we should cut out saturated fats completely from our diet. Regardless of the nature of the fat (unsaturated or saturated), if a fat is heated beyond its smoke point, it releases free radicals. Unsaturated fats have a lower smoke point and thus should not be used in cooking, only as dressing. For saturated fats, the higher the smoking point, the better the fat for cooking. Example: Clarified butter (ghee) is better than regular butter to cook with because it has a higher smoking point. (Takeway: Eat your salads with extra-virgin olive oil, and cook with butter, or ghee. Keep red meat consumption low and non-charred. Eat plenty of fish but make sure it is wild-caught. Also be careful of mercury levels in big fish such as tuna).
Trans fats are partially-hydrogenated unsaturated fats (if you fully-hydrogenate them, they become saturated and not trans). Partial-hydrogenation is used in some processed foods to lengthen shelf-life and decrease the need for refrigeration. Eating too many trans fats will lead you directly to the kitchen sink of all ills (obesity, high blood pressure and heart disease).*1 (Takeaway: Do not eat foods that are highly processed and do not eat foods that were fried - where fats are heated beyond their smoking point).
If you read thus far, you are in luck, because you are standing at the precipice of the most important part of this article. The science of "when to eat" is relatively new and incredibly exciting.
When to Eat
In a study performed in 2012, researchers looking to identify how much of disease is due to poor diet versus random eating throughout the day found that mice fed a high-fat diet (previously thought to be the cause of obesity) did not become obese if their time window for eating was restricted to 8 hours during the day.*2 Now go back and read that sentence again and marvel at how magical that sounds. This and later studies basically say that disease may not be the result of bad foods but of when you eat them. This is not a call to action to start binge eating junk food in an 8 hour window. Rather, if you eat less than perfect some of the time (which is all of us), you can still be protected from disease or weight gain if you eat within your 8 hour window most of the time.
What the scientists did with the mice in the above study is called "Time Restricted Eating" (TRE) where all calories for the day are consumed in a certain window of time during the day. The shorter the window, the greater the benefits and you can be doing a 16:8, an 18:6 or even a 22:2.
Intermittent Fasting (IF) is sometimes used interchangeably with TRE, but they are not exactly the same thing. TRE is a form of IF. There are other types of fasting such as alternate-day fasting or periodic fasting (such as 5:2, 5 days of regular eating followed by 2 days of full fasting).
Overall, Peter Attia, MD, who owns a longevity practice in NYC and the host of the popular podcast "The Drive with Peter Attia", calls these three considerations of how much to eat, what to eat and when to eat "the three levers" and encourages us to:
Always pull one,
Often pull two,
Occasionally pull all three levers.
Meaning, on any day, we should be doing at least one of eating the right amount of calories, eating during a restricted window (at least 12 hours but less is better) or eating the right foods. Often (maybe 5 out of the 7 days a week?), we should be doing two of these things and occasionally (maybe 1 out of the 4 weeks in a month?), we should be doing all three. This is amazing advice that I personally follow!
*1 Kummerow FA, Zhou Q, Mahfouz MM, Smiricky MR, Grieshop CM, Schaeffer DJ (April 2004). "Trans fatty acids in hydrogenated fat inhibited the synthesis of the polyunsaturated fatty acids in the phospholipid of arterial cells". Life Sciences. 74 (22): 2707–23. doi:10.1016/j.lfs.2003.10.013. PMID 15043986.
*2 Megumi Hatori, Christopher Vollmers, Amir Zarrinpar, Luciano DiTacchio, Eric A. Bushong, Shubhroz Gill, Mathias Leblanc, Amandine Chaix, Matthew Joens, James A. J. Fitzpatrick, Mark H. Ellisman, Satchidananda Panda. "Time restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high fat diet" Cell Metab. Author manuscript; available in PMC 2013 Jun 6.Published in final edited form as: Cell Metab. 2012 Jun 6; 15(6): 848–860. Published online 2012 May 17. doi: 10.1016/j.cmet.2012.04.019 PMCID: PMC3491655