Raise your hand if you grew up in a house full of low-fat everything — low-fat yogurt, low-fat salad dressing, low-fat crackers. The low-fat craze of the 90s was real, and it had everyone convinced that dietary fat was the enemy. Fat makes you fat, right? Not quite.

So what’s the real story on dietary fats? In this post and podcast episode, I break down everything you need to know about fats — the different types, what they do in your body, how they can aid or stall weight loss, and the simple shifts that can help you eat fat strategically without fear or confusion.

What Is Dietary Fat?

First, let’s clarify: dietary fat (the fat in food) is different from body fat (the fat in your body). This post is about dietary fat — one of the three macronutrients alongside carbs and protein.

Fat is made up of molecules called fatty acids, and your body needs them for more than just energy. Fat helps your body absorb vitamins A, D, E, and K. Fat also supports hormone production, protects your organs, insulates your body, and — let’s be honest — it makes food taste really good. 

So why does it get a bad rap? Mainly because it’s more caloric per gram than carbs or protein. Fat has 9 calories per gram, compared to 4 calories per gram for both carbs and protein. The caloric density of fat is partly what fueled the low-fat craze. The logic was simple — fat has more calories, so eating less fat means fewer calories, which means weight loss. The problem? It didn’t exactly play out that way. Food manufacturers replaced fat with sugar and obesity rates soared.

Here’s what you need to know: eating more calories than your body needs from any macronutrient (carbs, protein, or fat) leads to weight gain.

The Different Types of Fat

While calories matter for weight loss, research shows that the type of fat you consume matters for both weight loss and overall health.

Here are the three main types of dietary fat:

1. Unsaturated fats are the “heart-healthy” fats — the ones you want to eat more of. They break down into two subcategories:
   1. Monounsaturated fats (MUFAs): Found in olive oil, avocado, nuts, and seeds. These help lower LDL (bad) cholesterol and raise HDL (good) cholesterol.
   2. Polyunsaturated fats (PUFAs): Found in fatty fish like salmon and tuna, as well as walnuts, flaxseeds, and chia seeds. These include omega-3s, which reduce inflammation and support heart and brain health.

2. Saturated fats are found in red meat, butter, cheese, full-fat dairy, and coconut oil. Saturated fat has been shown to raise LDL (“bad”) cholesterol. But the science here is more nuanced than “saturated fat is bad.” We don’t eat nutrients in isolation — we eat foods. For example, full-fat Greek yogurt has saturated fat, but it also has probiotics, calcium, and protein. Red meat has saturated fat, but so does coconut oil. Coconut oil has been shown to raise LDL cholesterol, but Greek yogurt hasn’t been shown to have the same effect, perhaps because of the beneficial nutrients it contains. One thing we do know is that replacing saturated fat with unsaturated fat is beneficial for heart health, so aim for most of your fats to be poly- and monounsaturated fats and enjoy saturated fat in moderation. 

3. Trans fats are essentially man-made, processed fats that can be found in some processed and fried foods. They have no benefit to our health. They’ve largely been banned in the United States. But if you see “partially hydrogenated oil” listed in an ingredients list, that indicates trans fats. Less is best when it comes to trans fats.

Here’s a simple visual trick: unsaturated fats are liquid at room temperature (e.g. olive oil, canola oil), while saturated fats are solid at room temperature (e.g. butter, coconut oil).

How Fat Affects Weight Loss

Fat is calorie-dense, so portions matter. But fat is also incredibly satiating — it digests slowly and helps regulate your hunger hormones, which means it keeps you full and prevents overeating later.

Research shows that low-fat and low-carb diets produce similar weight loss outcomes. What matters most is staying in a slight calorie deficit and hitting your protein needs. Fat and carbs can flex within that framework, and some people find it easier to eat less fat, while others prefer fewer carbs.

For most women, the general recommendation is that 20–35% of daily calories come from fat — roughly 45–70 grams per day. But this doesn’t mean you have to track grams of fat. Instead, try this simple habit: start measuring your fats. One tablespoon of olive oil is 120 calories. An ounce of cheese is around 100 calories. These add up quickly when you’re not paying attention. If you’re eating all the right things but the scale isn’t moving, audit the portion sizes of fats you’re eating. 

Common Mistakes Women Make with Fat

Eating low-fat everything. Low-fat products often have added sugar to make up for lost flavor. You may end up hungrier and eating more overall. In my opinion, you’re better off with a little fat and less sugar than low-fat and more sugar. Enjoy some full-fat Greek yogurt — you’ll likely stay fuller longer.

Eating healthy fats – but too much. Olive oil, avocado, salmon, nuts, and seeds are all healthy fats, which are great to consume for overall health, but the calories still count and can add up quickly. Your fat intake might be creeping well above your calorie needs without you realizing it. Simply starting to measure these foods – such as keeping olive oil to one tablespoon – can help you start to create a calorie deficit without needing to count calories. 

Avoiding fat. Your body genuinely needs fat — for vitamin absorption, hormone production, brain health, and satiety. Cutting it out entirely backfires.

Easy Ways to Add Healthy Fats to Your Plate

Here are some simple, delicious ways to include healthy fats throughout the day:

• Cook with olive oil instead of butter most of the time
• Add avocado to toast, sandwiches, or eggs
• Have salmon or tuna a couple of times a week – canned counts!
• Sprinkle chia seeds, flaxseeds, or walnuts on oatmeal or yogurt
• Snack on apple slices with peanut butter or a small handful of nuts

The goal is a small source of fat at every meal, paired with your protein and carbs for a truly balanced plate.

The Bottom Line

Fat is not the enemy. But it does have more calories per gram compared to carbs and protein, so portions matter. The type of fat also matters. Focus on olive oil, avocado, nuts, seeds, and fatty fish. Enjoy butter, cheese, and red meat in moderation. 

Want help putting all three macronutrients together on one balanced plate?

Download my free guide: 5 Habits for Sustainable Weight Loss for Busy Moms — it walks you through the exact portions of protein, carbs, and fat to put on your plate to help you burn fat.