The Renaissance Diet 2.0. Mike Israetel
for neuronal firing in the central nervous system and muscle contractions in cardiac, smooth, and skeletal muscle tissue. Electrolyte balance also mediates hydration and blood pH–though only very severe imbalances can disturb blood pH as it is very tightly regulated.
It is important to replace electrolytes and fluids during activity, particularly if the activity is sweat-inducing: high intensity, prolonged duration, or occurring in a hot and humid environment. During and after such activity, electrolytes can help the body return to a homeostatic state. Consuming additional electrolyte beverages during such training is recommended.
Daily electrolyte needs for rest or light training are usually achieved with normal food consumption. Most people meet daily requirements of sodium and chloride easily as these two minerals are what make up table salt and are found in many foods and other seasonings.
Magnesium is also found in a variety of food products, such as spinach, beans, shellfish, and milk. The primary dietary source of calcium is usually dairy, but almond and soy milk as well as dark green leafy vegetables contain small amounts as well. Potassium can be found in most fruits and vegetables, with white potatoes and bananas having the highest amounts. Dietary sources of iron are divided into two categories, heme and non-heme iron. Non-heme iron is present in an oxidized form that must be reduced before it can be absorbed. Because it does not have this need for reduction, heme iron is absorbed at a much greater rate than non-heme iron. Heme iron comes mainly from meat, fish, and poultry. Non-heme iron can be found in plant sources, such as whole wheat and dark green vegetables.
Many people do not consume adequate amounts of iron; this is particularly true of vegans, vegetarians, and females of childbearing age, particularly if they experience heavy menstrual bleeding. For athletes this can be especially problematic. Chronically inadequate iron intake or absorption results in iron-deficiency anemia, which is a decrease in the number of healthy red blood cells able to carry oxygen. This means a decrease in the blood’s ability to deliver oxygen to working tissue where it is needed to produce energy for muscle contractions. Anemia can hinder high-volume weight training and cardio, as well as recovery from physical activity. A dietary supplement of iron may be needed for those limiting or avoiding the consumption of animal products, under-eating heme-iron for any reason, or those prone to iron deficiency.
Fiber
Dietary fiber is not digestible by humans, but some types can be fermented in the human gut by the microbiome. Because the absence of fiber does not result in a nutritional deficiency, it is not technically an essential nutrient, but it is an important part of a healthy diet and has many health-, fitness-, and diet-related benefits. In addition to possible heart health benefits and bowel movement regularity, fiber increases feelings of satiety. This can be helpful on a fat-loss diet.
Further, fiber slows digestion, which can help maintain steady blood glucose by decreasing the glycemic index of faster digesting carbohydrates during periods of lower activity.
Phytochemicals
Phytochemicals are chemicals found in plants. Although no phytochemical has been identified as an essential nutrient, some have potential health and fitness benefits. While research is still actively determining potential effects of many phytochemicals, there is strong evidence that many contribute to lower rates of cancer and heart disease and some suggestion that they can promote improved overall bodily function. While recommended intakes for most have yet to be agreed upon or set, you can likely get most beneficial phytochemicals by consuming multiple servings (a serving is generally defined as 1 cup cooked or 2 cups raw) per day of fruits and vegetables. Varying the types of fruits and veggies and being sure to include an assortment of brightly colored options as well as leafy greens will help ensure consumption of an array of phytochemical nutrients and their potential health benefits.
HOW FOOD COMPOSITION FITS INTO THE DIET PRIORITIES
The combined effects of all food composition choices contribute only 5% of potential fitness outcomes. This means food composition choices for any one macronutrient source will make only a percent or two of difference. Transitioning from terrible carbohydrate composition choices to perfect ones would probably result in barely notable physique and performance changes even over the course of months. That being said, the effects on long-term health of such a switch are much larger. Your long-term ability to pursue and cultivate fitness rests on the foundation of your overall health. Across a lifetime, the indirect effects of good food composition choices on physique and performance might add up to well over 5%. In other words, you can get in shape eating pop tarts and potato chips for carbs, but if you want to stay in great shape for decades, switching to mostly veggies, fruits, and whole grains is likely a better strategy.
In most cases, you can reap the full benefit of good food composition as long as you get around three-fourths or more of your intake from recommended sources of protein, carbs, and fats. Getting the rest from processed junk food will come at little or no detriment to your training and physique goals. This is because the value of good food composition is in getting enough of certain nutrients.
Once the required values of these nutrients have been met, more of them do not necessarily provide additional benefit. For example, if your fat intake is predominantly monounsaturated fats and you meet your essential fat needs regularly, some saturated fats and even a bit of trans fat intake from junk food occasionally has not been shown to negatively impact health, performance, or body composition. The downside of junk food is that it lacks these healthy micronutrients, so adding some junk once you have the minimum of all these micronutrients has no significant downside if properly moderated. Having some leniency in your diet regimen can relieve some of the stress of diet discipline and improve adherence.
Finally, when reviewing your diet program for food composition, it is important in any case to be wary of macro extremes. If an entire macro category is very low, perhaps at the tail end of a fat-loss diet when fats have been dropped to their minima, the food composition of the fat source begins to matter to a greater extent. At this point, it might be wise to supplement Omega-3 fats to ensure that at least essential fat needs are met. In more extreme cases, when fats are at their lowest and carb cuts are needed to continue fat loss in the final weeks of a hypocaloric diet, it is probably time to exchange the workout carb powders and white rice for more veggies and fruits so that your micronutrient intake remains at a healthy level. Vitamin supplements at this point might also be warranted.
CHAPTER SUMMARY
•Food composition describes the quality of food in terms of its digestibility, digestion rate, and the micronutrients and fiber content.
•The quality of protein is largely determined by the essential amino acid profile and its digestibility and, to a smaller extent, by its micronutrient content.
•The quality of carbohydrate is primarily determined by the digestion rate, or how quickly it can be absorbed into the bloodstream, and its micronutrient and fiber content.
•The quality of fat is primarily determined by the class of fat, and diets should generally prioritize monounsaturated fats, polyunsaturated fats, and saturated fats, in that order, while keeping trans fat consumption to a minimum.
•A well-balanced diet will generally meet all the daily micronutrient requirements; however, during hypocaloric periods and periods where certain macronutrients are deprioritized, a vitamin supplement can help ensure micronutrient values are met.
CHAPTER 6
Supplements and Hydration
The final 5% of dietary outcomes comes from a combination of supplement consumption and hydration management. You might be wondering why water intake, which is necessary