Lean body weight protein requirements + GDA

Question

Using the calculator: http://lowcarbdiets.about.com/library/blbodyfatcalculator.htm, I've finally had a chance to work this out properly by measuring myself as last time I did it based on guesses.

Apparently I have 28.9% body fat. I weigh 95kg, so that means my lean body weight is 67.55kg. If you're supposed to have 0.5g of protein per kg of lean body weight, that means I should be getting around 34g of protein daily.

Therefore, if my BMI to lose weight (1lbs weekly) is 1525 calories daily, I am getting the following figures for GDA:

zero exercise days
calories                1525
protein                 34
carbohydrate (max)      183
- of which sugars       73
- dietary fibers        24
fat (max)               58
- of which saturates    18
sodium                  3

According to a previous question, we should be getting atleast 100g carbs daily. What is the minimum fat I should be getting if 58g is the max? And is it normal that the GDA above allows me to have more fat than protein?

Answer 1

According to the Nutrition Textbook I have, there are only established AI's (adequate intake levels) for two particular types of fat: linoleic acid (an omega-6 fatty acid in nuts, seeds, soybean oil, safflower oil, and corn oil) and alpha-linolenic acid (an omega-3 fatty acid in soybean and flaxseed oil). The body can synthesize all the other types of fat it needs from these two. To make a long story short, omega-6 fatty acids are inflammatory and omega-3 fatty acids are anti-inflammatory, so they work together to keep the body in balance.

Males aged 19-50 require 17g of linoleic fatty acid per day and females in the same age group require 12g/day. The respective values for alpha-linolenic acid is 1.6 and 1.1 g respectively. Since omega-3 and omega-6 fatty acids work in opposition, it is important not to overconsume one and neglect the other. An optional guideline: according to the National Academy of Sciences Institute of Medicine Food and Nutrition Board, up to 10 percent of the AI for alpha-linolenic can be consumed as EPA and/or DHA, which are omega-3 fatty acids found in fish. DHA and EPA have more potent anti-inflammatory effects than alpha-linoleic acid, but they can be synthesized from it if needed.

This doesn't mean you should try to cut out all other types of fat. Healthy, whole foods have a variety of fats and other nutrients in them. Fats also help lower glycemic index and carry vitamins. Certain diets, such as ketogenic diets (very low-carb), have higher requirements for fat-intake, so you should also look into diet-specific recommendations.

Since the GDA for protein in a minimum and the GDA for fat is a maximum, I think it makes sense that the value for fat is more than protein.