Dietary Fat – the Good, the Bad, and the Ugly

Listen to my podcast where I will discuss what you need to know about how much fat to get per day, which types of fat to get more of, and the types to cut back on, here: Dietary Fat – the good, the bad and the ugly

February 2017: the written content below has been updated to reflect new research relevant to this article.

Even after many years of media hype about healthy fats and negative fats for health, I still find that many of our clients are confused about dietary fat. Here is what you need to know about how much fat to get per day and which types of fat to get more of and those to cut back on.

How much dietary fat is recommended per day?

The amount of dietary fat you need per day is based on a percentage of total calories. You may have heard in the media that less than 30% of your calories should come from dietary fat – in fact this is an average and there is really a range. The following chart suggests the goals for the percentage of total calories recommended from dietary fat based on age.

*Based on the goals for percentage of daily calories suggested by the Dietary Reference Intakes. Acceptable Macronutrient Distribution Ranges. Food and Nutrition Board, Institute of Medicine, National Academies. 2005.

If you are curious how many grams of fat you need per day based on the above percentage goals a moderately active female adult that needs 1800-2100 calories per day would require 40-82 grams of dietary fat per day. A moderately active male adult that needs 2400-2700 calories per day would require 53-107 grams of dietary fat per day.

The Good

Unsaturated fats (polyunsaturated and monounsaturated fats) found in vegetable oils such as olive oil, nuts, seeds, avocados and fish are healthy fats that are good for us. Be sure to include a moderate amount of these in your diet, as they lower your “bad” or LDL-cholesterol. One type of polyunsaturated fat known as the omega-3 fats improve heart health by making the blood less sticky, which reduces the risk of heart attack and stroke. Omega-3 fats also lower blood pressure and blood triglyceride levels and are helpful for immune and inflammatory based issues. Omega-3 fats are important for pregnant women for brain and nervous system development of babies. The best sources of omega-3 fats are fatty fish and other sources include ground flax seeds, walnuts, hemp seeds and canola oil.

The Potentially Bad

Traditionally it was thought that saturated fat was harmful for heart health.  Saturated fats are found in heavily marbled meats, the skin on poultry, butter, margarine, tropical oils (coconut oil, palm oil, cocoa butter), and high fat-dairy foods such as cheese.  Newer research has found that saturated fats may or may not increase the ‘bad’ LDL-cholesterol in the body, which harms heart health. Part of the reason that there may be some conflicting results depends on which foods are being replaced for saturated fat.  Monounsaturated fats (found in olive oil, nuts and avocado) as well as omega-3 fats (found in fish) when replaced for saturated fat is beneficial for heart health.  Health depends on the quality of your whole diet, not just the type of fat or any other single nutrient.  Rather than focusing on counting grams of fat, focus first on eating wholesome foods your grandmother would recognize that contain simple ingredients.

The Ugly

Trans fats (shortening, hydrogenated vegetable oils) are found in some margarines and some packaged foods such as cookies, cakes, frozen meals, deep fried foods, and fast foods. The food label can help you determine how much trans fats are in a particular food. Aim to reduce or even eliminate trans fats from your diet since they not only increase the “bad” LDL-cholesterol but they also reduce the “good” HDL-cholesterol in our body. Trans fats also increase blood vessel inflammation that increases the risk of other chronic conditions.

What about dietary cholesterol?

Be aware that dietary cholesterol is different than the cholesterol found in your blood. Although foods such as eggs or shrimp are high in dietary cholesterol, they are low in saturated fat and therefore have limited influence on cholesterol levels in your blood. This is good news if you enjoy eggs for breakfast or grilled shrimp on the barbeque.