Amped Training

Regarding fat intake, you'll hear anything from ZOMG FAT EVAL!! to people that think fat should be a major source in the diet (ketogenic eating).

The truth, as usual in this type of thing, is somewhere in the middle. You need fat in your diet, for a whole lot of things. Along with protein, fat comprises most of your tissues that aren't water. Fats are stored in adipose tissue as triglycerides, which also provide a source of fuel for aerobic metabolism when released into the bloodstream.

There are different types of fat, which fall into the categories of saturated, monounsaturated, and polyunsaturated (which includes the essential fats).

Essential fats are divided into the omega-6 and omega-3 categories, derived from two polyunsaturated fats called alpha-linolenic acid and linoleic acid. Essential fats are crucial to a number of processes, including inflammation and healing as well as neurological and cardiovascular health. The omega-3s in particular have also displayed a positive effect on partitioning away from fat cells and towards muscle, although this is a subtle, long-term benefit.

Virtually all of the essential fats are derived from polyunsaturated fat, and these include flax, canola, safflower, and borage oils, certain nuts, and fish. Plant sources do not contain EPA (eicosapentaenoic acid) or DHA (docosahexaenoic acid), which are the two omega-3 fats. These are found in fish and fish oils.

The essential fats can all be synthesized to some degree or another from other omega-6 or omega-3 fats, but having a dietary source of EPA and DHA is valuable as this conversion does not always provide adequate amounts.

In terms of daily recommendations, fat intake generally falls around 0.5g per pound, although this is a fairly arbitrary intake. In situations of lowered carb intake, dietary fat is used as “caloric ballast” to fill the remaining energy requirements once protein reaches the desired levels. Regarding essential fats, the only suggestion is to get 5-10g of omega-3s per day from dietary sources (fish oil is a good place to start).

As a rule of thumb, any remaining fats should come from other polyunsaturated sources, or from monounsaturated oils like olive oil. Olive oil in itself is an overall “healthy food”, containing large amounts of vitamin E and known as having strong antioxidant properties.

Saturated fats from animal sources are generally not desired as large parts of the diet, but like everything else it's not an all or nothing proposition. Getting a little in won't kill you, and is likely beneficial.

In addition to this, there are also the medium-chain triglycerides (MCTs) and diaglycerol (DAG) oils which can be a part of fat intake. These fats differ from others in that they are preferentially used for energy by the body, which can make them useful in periods of lowered carb intake. Both of these have been implicated in metabolic increases and positive changes in body composition, but so far as I can tell there's nothing actually supporting that claim. Coconut oil is a good source of MCTs (although it is high in saturated fat). DAG oil can be purchased under the label Enova Oil.

Contrary to popular belief, dietary fat does not make you fat. Eating too much, period, makes you fat. Now, strictly speaking, fat absorbed into the bloodstream from the gut does enter fat cells. The issue is, in a calorie deficit, it simply doesn't stay there. This is not a matter of insulin, or clean eating; it's a simple fact that the body is not going to store energy when it cannot fuel its basic functions. The body is designed for survival, and storing valuable, needed energy when it's already not able to cover its basic needs is not a survival strategy.

Thermodynamics will win out over insulin every time.

Certain diets that are moderate in protein, high in fat, and very low in carbs have shown themselves to have interesting effects in the body. In a chronically carb-deficient state, the body metabolizes fat into compounds called ketones, which can be used for fuel in place of glucose, albeit in a limited sense. Being in ketosis is often accompanied by fatigue, mental “fuzziness”, and occasionally with a feeling of having extra energy due to an increase in catecholamine levels.

Interestingly, these ketogenic diets have shown fat losses with calorie intakes closer to maintenance level than “glucose based” dieting, and studies have been done showing no negative impact on lipid profiles (cholesterol, triglyceride levels, etc).

This is not to say that ketogenic diets are somehow superior to other approaches. Rather, it's to point out that high fat intakes do not correlate with body fat. Calorie balance is the ultimate determinant, followed by essential protein and fat intakes.