Different types of fat have different effects on your cholesterol levels. Saturated fats and trans fats raise bad cholesterol (LDL) levels in your blood, while monounsaturated fats and polyunsaturated fats can lower them.

While your body does need some triglycerides for energy, having high triglycerides can increase your risk of heart disease and may be a sign of metabolic syndrome. Causes of high triglycerides include obesity, kidney disease, hypothyroidism, poorly-controlled diabetes and certain medications.

Studies have shown that eating a high-fat diet can alter signaling mechanisms in the brain, which may lead to depression symptoms. Eating foods high in trans fats is also linked to decreased serotonin (sometimes called the 'happy chemical') levels. However, research shows that eating a diet high in healthy fats (e.g., avocado, olive oil, seeds) can actually contribute to positive mental health.

Most nutritionists recommend replacing saturated fats and trans fats with monounsaturated fats and polyunsaturated fats. Pay attention to labels when you’re shopping. Don’t be fooled by foods that say “0 trans fat,” as they can contain a lot of saturated fats and/or be high in added sugars.

In addition to carbohydrates, fat provides energy for workouts and helps your body absorb vitamins. Look for healthy unsaturated fats (nuts, olive oil, avocado) to fuel your fitness routine.