Monounsaturated fats are found in plant sources, such as olive oil, canola oil, avocados, and a variety of nuts. This fat type not only promotes better health than others, but also, to some extent, supports leaner, more muscular physiques. Fat in any diet focused on health, performance or body composition should come primarily from monounsaturated sources.
Polyunsaturated Fats
Polyunsaturated fats can be found in certain vegetable oils, such as canola oil and safflower oil; walnuts; many fatty seeds; and some animal products like fatty fish and grass-fed animal meat. The most nutritionally relevant are the essential fats, Omega-6 and Omega-3 fatty acids. In most modern diets, Omega-6 fats are consumed in sufficient quantities, but Omega-3 fats are often under-eaten. This means that those training for high levels of fitness might need to supplement Omega-3 fats or tailor their diet especially for these fats. A diet relatively high in polyunsaturated fats supports performance well and is relatively neutral for general health.
Saturated Fats
Saturated fats come mainly from animal sources, such as dairy, eggs, meats, and coconut oils. Opinion on saturated fat has swung from recommended consumption of steak and eggs prior to marathons in the 1970s, to its demonization in the 80s and 90s, and back to an overemphasis on its consumption in the 2000s with bacon-and-heavy-cream-based, low-carb diets. Today, if we look at the data on saturated fat and health as a whole, they suggest that too much saturated fat can have a negative impact on health. On the other hand, saturated fat might have a positive effect on anabolic hormone levels for those interested in physique and sport performance. More data is needed for saturated fat recommendations in terms of potential physique benefits, but health detriments currently support limiting saturated fat intake.
Trans Unsaturated Fats
Trans fats are unsaturated fatty acids–as described briefly in chapter 3, trans or its counterpart cis, refer to the configuration of the fat molecules’ functional groups. Different configurations have different biological and chemical properties. Trans fats occur only rarely in nature and in small quantities. This class of fats is mainly produced during the chemical manipulation of naturally occurring fats. These manipulations are made to achieve distinct advantages for food production and distribution. Some of these alterations of molecular structure allow fats that would normally be solid to remain liquid at room temperature. This makes them appealing as cooking oils and for use in baked or fried foods that have to be stored at room temperature.
Also, in part because of their unique chemical nature, trans fats are not nearly as likely to go rancid or be consumed by bacteria, increasing safety for the consumer and extending the shelf life of the product. This means that foods can be shipped farther and stored longer, which can be critical in emergency aid situations and in places where refrigeration and access to food are limited.
As big a boon as trans fats are for preserving food and reducing foodborne illness, they also have a substantial downside. Most studies show that high levels of trans fat consumption results in increased likelihood of negative health effects such as higher rates of cardiovascular and other systemic diseases. One primate study suggested that diets high in trans fats might also lead to decreased muscularity and increased fat mass, suggesting a potential contribution to changes in body composition. Avoiding trans fats as much as possible is therefore likely the best advice from both health and fitness standpoints. That being said, it is unlikely that the occasional indulgence within an otherwise healthy diet will have significant effect.
Fat Source Micronutrient Density
Many fat sources do not contain other nutrients, so micronutrient density contributes far less to the compositional quality of fats than it does for other macronutrients. Fat is the only way to transport fat soluble vitamins, but the vitamins come from other food sources in most cases and are merely facilitated by proximal fat consumption. The way the different types of fat are digested and stored constitute the most meaningful differences in composition.
In table 5.3, we have parsed fat class information into estimated percentage recommendations for the daily intake of each type of fat. Bear in mind that these are estimates, not exact numbers to hit daily. In general, acquire most of your daily fats from monounsaturated sources, take in enough Omega-3s, be moderate with saturated fats, and avoid most trans fats in your regular diet.
Table 5.3 Suggested range of intake as percentage of total daily fat intake for the four types of dietary fat.
| Fat Intake Recommendations | |
| Fat Type | Recommended % of Daily Fat Intake |
| Monounsaturated | 45 - 60% |
| Polyunsaturated | 35 - 50% |
| Saturated | 5 - 20% |
| Trans fats | < 1% |
THE MICRONUTRIENTS
Vitamins
Vitamins are a class of micronutrients composed of vitamins C, A, D, E, K, and the B-complex vitamins. Water-soluble vitamin C and B-complex vitamins are found in most fruits, vegetables, and some grains, with the exception of B12, which is found in seafood, meat, dairy, and eggs. The fat-soluble vitamins A, D, E, and K are found in vegetable oils and dairy products. Most vitamins are converted to an active form upon entering the bloodstream at which point they regulate numerous body processes from vision to energy metabolism to bone formation.
Water-soluble vitamins bind to water molecules in the digestive tract and freely move into the bloodstream. Fat-soluble vitamins, on the other hand, must bind to dietary fat in the digestive tract in order to be absorbed and used. Diets that are chronically low in fat can result in a fat-soluble vitamin deficiencies.
When consuming a balanced diet, vitamin deficiencies are rare, but possible. Eating multiple servings of fruits and vegetables per day and consuming adequate amounts of grains, proteins, dairy, and healthy fats can decrease the chance of developing these deficiencies. Food variation across the week can also help as vitamin levels vary between different fruits, vegetables, and grains. For best health and fitness make sure your food choices contain adequate vitamins. Vitamin supplements are an effective option, though you should not program your diet such that you are relying entirely on supplements for your vitamin intake over long-term periods. When on a hypocaloric diet, it can be a good idea to take a once-a-day multivitamin as an insurance policy, though this is not a substitute for making generally healthy choices.
Minerals
Dietary minerals are naturally occurring chemical elements required by the body for basic function and health. Essential minerals include calcium, phosphorus, magnesium, and iron. Trace minerals–those needed in very small amounts, but potentially toxic in large amounts—include zinc, copper, manganese, iodine, selenium, molybdenum, and chromium.
Although all essential minerals are necessary for health purposes, for body composition and performance considerations, a subgroup of minerals called electrolytes are probably the most important. Electrolytes such as sodium, potassium, chloride, calcium, iron, and magnesium carry a positive or negative charge. This charge can impact cell function by altering cell membrane permeability. Such