Dietary fat is absolutely critical. It is needed for cell membrane construction, hormone production, and fat-soluble vitamin absorption. Having adequate fat in the diet can have a favorable impact on satiety.
Specific dietary fats – omega-3 and omega-6 fatty acids – are also essential nutrients that are required to regulate inflammatory signaling. Finally, very low dietary fat intake may be associated with an increase in hunger, and a decrease in sex hormone production.
How much fat should you eat?
Most public health agencies recommend that dietary fat should account for 20-35% of total energy intake in your diet.
However, this number doesn’t work equally well across the entire energy intake spectrum. So, it’s also a good idea to establish a lower limit for fat intake, just to make sure that this percentage-based range doesn’t lead to insufficient fat intake when Calories are low.
How to calculate your lower limit for fat intake: If you subtract 150 from your height (in cm), then multiply the outcome by 0.5 and add 30, this should give you a good estimate of your lower boundary. If you’re under 150cm tall, you probably want to ignore this equation and set your lower boundary to an even 30g/day.
Furthermore, higher fat intakes can also coincide with a healthy and nutritionally complete diet. For example, lower-carb, higher-fat diets with a large amount of animal products generally have worse mortality outcomes (likely owing to the saturated fat content of animal fats) than diets with more moderate fat and carbohydrate distributions, but lower-carb, higher-fat diets with more plant-based foods generally lead to similar or better mortality outcomes.
In short, there’s a pretty wide range of acceptable dietary fat intakes.
What about saturated fat and trans fat?
When it comes to specific types of fat, a simple but effective strategy is to limit artificial trans fats as much as possible, and to get a roughly even split of dietary fat from monounsaturated, polyunsaturated, and saturated fats.
Keeping a decent amount of polyunsaturated fat makes it easier to consume plenty of EPA, DHA, and essential fatty acids. Keeping a decent amount of monounsaturated and saturated fat in the diet appears to support sex hormone production pretty effectively.
Most guidelines related to cardiovascular health advise keeping saturated fat to no more than 10% of total energy intake, so if you follow the recommendation of getting 20-35% of Calories from total fat with an even mixture of monounsaturated, polyunsaturated, and saturated fat, you’ll be under or close to that limit.
There are several different types of dietary fats, which all have a place in a balanced diet
Learn more about dietary fat, including signs of deficiency/insufficiency and recommendations for good sources of fat, in this knowledge base article.