What you‘ve just learned isn‘t an invitation to consume unlimited fats, animal or vegetable alike, as Dr. Atkins once recommended. Dietary fat digests almost completely and the excess is deposited under the skin as fat for storage. The “excess” is the difference between the fat used by the body for energy and plastic needs (to make cells, hormones, etc.) and all digested fat.
Your energy needs vary, depending on your carbohydrate consumption. The plastic needs are in the ballpark of 1 gram per 1 kg of body weight. In other words, if you consume adequate amounts of carbs and proteins, and weigh 70 kg, consuming about 100 g of fat will not increase you weight. (The extra 30 grams are for losses from stools, cellular uptake in the intestines, and inefficiency in digestion.)
The longevity diet (i.e. basic nutrition) is naturally moderate-to-low in fat, because natural meats, fowl, fish and seafood, and fermented dairy are relatively low in fat. In fact, most of the excess of fat consumption in the American diet is coming from vegetable oils well hidden in fried foods, sauces, dressings, and mayonnaise. If you exclude all vegetable oils from your diet, you aren‘t likely to consume excess animal fat, unless you do it consciously and intentionally.
Also, note that sometimes I recommend an increase in animal fat (butter) consumption because it‘s essential to overcome digestive disorders and related conditions. Once you normalize your situation, you can resume moderate fat consumption.
Finally, if you are overweight, then, with the exception of essential fatty acids from liquid fish oil, you don‘t need any additional fat. Your body will supply all the fat you need for energy and plastic metabolism. This is, in fact, the most reliable method of weight loss. Still, you need to consume moderate amounts of fat to prevent hepatic and intestinal dysfunctions, listed in the bullet points below.
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