What Is The Best Diet?

Diets

The best diet is the one that works for you, that allows you to feel comfortable in your skin, literally and figuratively. All “diets” are restrictive, in calories, categories of food, or when and how you eat. Let’s consider a few.

See-food – This is by far and away the most common diet. We see something tasty, often something engineered to create that response in us, and we eat it. While we are “restricted” by what we can see and desire, it often meets our emotional rather than nutritional needs. 

Calorie-restricted – This is the classic based on the “calories in should equal calories out” model. It is more nuanced. Your body recognizes the dwindling calories and turns down your metabolism, reducing calories out to match calories in – very frustrating. This is often accompanied by increasing exercise, which helps, but not as much as we hope. Thirty minutes of “all-out” on my Peloton is one donut equivalent — thirty minutes of sweat for two or three minutes of tasting pleasure.

Category-restricted – Probably the most common diets after see-food. They are all based on one or another category of foods being bad. The underlying definition of bad may be nutritional, anthropologic in Paleo, geographic for the Mediterranean diet, or ethical, in vegan and vegetarian diets.

Nutrient-restricted Low carbohydrate is one of the oldest and goes by many names. In addition to reducing your intake of carbohydrates, it increases your fats or proteins in some combination. Carbohydrates, another name for sugar, are “bad” because, as our body’s source of instant energy, they provide a very short moment of pleasure and satiety, a sugar rush. The glycemic index seeks to identify carbs that hang around longer, increasing the satiety without sacrificing happiness. A low carbohydrate diet will frequently identify low glycemic index carbs as better but not best.

When you deny your body its short-acting fuel, it turns to its long-acting source, fats. Fats are the most calorie-dense nutrient and more effective than carbs at quelling your hunger – you are satisfied longer. By increasing your dietary fats, you continue to provide energy. By simultaneously limiting your calories, you hope that some of the fat you burn comes from your body, not your plate.  

Protein is probably the most satiating category, with a calorie density just slightly greater than carbohydrates. There are no diets that restrict protein because our bodies do not store protein; all of it is functioning. Lower body protein results in impaired body function, and that includes our immune response. Low carbohydrate, high protein diets burn more of your body fat, and energy comes from the less efficient protein conversion into sugar. That conversion creates more “waste” products that need to be eliminated through your urine, and for some individuals, this may stress their kidney function. 

Paleo is based on the idea that our body’s metabolism has not evolved in synchrony with our evolving food technology. Our 12,000-year-old metabolism is not suited for a diet where canned food is only 200 years old, and Oreo’s are just over 100. The diet our metabolism is best suited for is therefore what we ate 12,000 years ago. This diet eliminates processed foods which are often calorie-dense and that, by intent or not, may be less satiating. The Mediterranean diet, like Paleo, seeks to match our metabolism better. Rather than guess what our paleolithic ancestors ate, it copies our Mediterranean ancestors' diet – fruits, vegetables, fish, less dairy, and meat. These diets focus less on nutrients and more on the totality or “wholeness” of a food. They are more holistic than reductive.  

Plant-based diets emphasize fruits and vegetables – foods that contain lots of water and therefore are less calorie-dense. They also have lots of fiber which slows absorption, lowering their glycemic index. Plants are not particularly high in protein, and plant-based diets vary quite a bit as to what foods supply that protein. Most of us, following a plant-based diet, are omnivores; meats and fish are still on the menu. We just eat less of them. Vegans only eat plants; they consume no animals and do not use animals’ products, like milk, cheese, and eggs. A vegan diet requires supplements, particularly Vitamin B₁₂, and attention to finding plant sources rich in proteins. B₁₂ is also needed by vegetarians, who will not eat mammals but may make exceptions for fish. Other vegetarian variants do or do not allow dairy products or eggs. 

Time-restricted diets are more concerned with when rather than what you eat. You restrict the hours of eating to less than the usual 8 hours of fasting we experience while sleeping. There are various regimens over hours or times of the day, but the result is that you often eat less. You certainly burn more fat because you restrict your energy intake to only a portion of the day. And there may be some underlying, ill-understood connection to our circadian rhythms – our sleep-wake cycles influence the coming and goings of our hormones, including those that help regulate our appetite. 

The best diet

That is easy, ask anyone, they will tell you it is their diet. In reality, the diet that works for you, that lets you achieve a weight that makes you feel good, physically and emotionally, is the best diet. The word diet is a misnomer, suggesting the what, when, and how of eating is somehow not integrated with how much you move about or sleep. Your diet is entangled in your lifestyle. At my age, a plant-based diet works; although a nice steak or shellfish calls to me, they call less often. 

Consider the advice of two nutritionists, Michael Pollan, who said, “Eat food, but not too much, mostly plants,” and Mary Poppins, who was heard to utter, “Enough is as good as a feast.”