Understanding Dietary Fat
Dietary fat has long been misunderstood. For decades it was blamed for weight gain, heart disease, and poor health. Today, we know that fat is not the enemy — context, type, and portion matter far more than avoidance.
This guide explains what dietary fat is, why your body needs it, and how to include it confidently and practically in everyday meals.
What Is Dietary Fat?
Dietary fat is one of the three macronutrients, alongside protein and carbohydrates. It provides 9 calories per gram, making it the most energy-dense macronutrient.
Fat plays essential roles in the body, including:
Hormone production (including reproductive hormones)
Absorption of fat-soluble vitamins (A, D, E, K)
Cell membrane structure and protection
Brain and nervous system health
Satiety and meal satisfaction
Removing fat from the diet is not supported by evidence and often leads to poor adherence, nutrient deficiencies, and increased reliance on refined carbohydrates.
Types of Dietary Fat (This Is What Matters)
Unsaturated fats support cardiovascular health and metabolic function.
Sources include:
Olive oil
Avocado
Nuts and seeds
Tahini
Olives
Fatty fish (for those who eat it)
Both monounsaturated and polyunsaturated fats are associated with improved lipid profiles when they replace saturated fat in the diet.
Saturated fat is found in:
Dairy
Coconut products
Butter
Some meats
Current evidence suggests saturated fat does not need to be eliminated, but should not dominate the diet. Health outcomes improve when saturated fat is replaced with unsaturated fat — not when fat is replaced with sugar or refined carbohydrates.
Industrial trans fats are associated with increased cardiovascular risk and should be avoided. They are largely removed from the food supply but may still appear in highly processed foods.
Fat and Body Weight: The Truth
Fat does not inherently cause weight gain. However, because it is energy-dense, portion awareness is important.
Fat contributes to:
Slower digestion
Increased fullness
Greater meal satisfaction
Meals that include fat are often more sustainable and help reduce grazing and overeating later in the day.
How Much Fat Do You Need?
There is no single ideal intake. Needs vary based on:
Energy requirements
Hormonal health
Training load
Food preferences
Most evidence-based guidelines support fat intakes ranging from 20–35% of total energy, with an emphasis on unsaturated sources.
Practical Tool: How to Include Fat Without Overdoing It
Use your hand as a simple portion guide:
1 thumb-sized portion of fats per meal
Up to 2 thumbs for larger bodies, higher energy needs, or very active individuals
Example:
1 tablespoon olive oil
¼–½ avocado
1 tablespoon nut butter
Small handful of nuts or seeds
1 tablespoon tahini or pesto
Fat and Blood Sugar Control
Including fat with meals:
Slows carbohydrate digestion
Reduces blood sugar spikes
Improves meal satisfaction
This is particularly helpful for individuals with insulin resistance, reactive hypoglycaemia, or a history of restrictive dieting.
Common Myths About Fat
“Fat makes you fat” → Weight gain results from sustained energy surplus, not one nutrient.
“Low-fat is healthier” → Many low-fat foods are highly processed and lower in satiety.
“Plant fats are unlimited” → Plant fats are healthy but still energy-dense.
Dietary fat is:
Essential
Satiating
Supportive of hormonal and metabolic health
The goal is not to fear fat or overconsume it, but to include it intentionally, prioritising whole-food sources and appropriate portions.
This article is for educational purposes and reflects current evidence-based nutrition principles.