Essential fatty acids: what happens if you don’t get them in your diet

Essential fatty acids matter more than most of us realize. If you skip them long enough, you’ll start feeling it in small, cumulative ways—like a quiet chorus turning into a loud clash. So what happens to these fats when they don’t show up in your diet? Let’s break it down in a clear, practical way.

What are essential fatty acids anyway?

Essential fatty acids (EFAs) are fats your body can’t make from scratch. That means you have to get them from food. There are two main families:

• Omega-3s, which include ALA (from plants) and the long-chain EPA and DHA (mainly from fish and algae).

• Omega-6s, with linoleic acid as the common plant-based source, and arachidonic acid in some animal foods.

These fatty acids aren’t just “fats.” They’re building blocks. They help form cell membranes, support brain and eye development, and guide countless signaling pathways that control inflammation, immunity, and metabolism. Think of EFAs as the raw material for a lot of the body’s most delicate and essential machinery.

Why the body can’t fake them

A lot of nutrients come with a little flexibility—your body can make them or substitute similar compounds. Not EFAs. The core reason is simple: certain fats are required as structural components and as raw materials for functions the body can’t perform well without. So, if you don’t get them from your diet, you don’t have enough to keep membranes flexible, hormones balanced, and signaling molecules properly formed. It’s not about cravings; it’s about biochemistry doing its job.

What happens when EFAs aren’t consumed

If your diet routinely lacks essential fatty acids, the body will eventually show signs of deficiency. Here’s what that can look like in real life:

• Brain and mood effects. EFAs play a role in brain cell membranes and signaling. In generous amounts, omega-3s are linked with better mood and cognitive function. In deficiency, some people notice mood fluctuations, brain fog, or slower reaction times. It’s not dramatic overnight, but the pattern can be noticeable over weeks or months.

• Skin and hair changes. You might see dry, scaly skin, dermatitis, or hair that’s not as resilient as it should be. The skin’s barrier function relies on fats, and when EFAs are scarce, that barrier can weaken.

• Inflammation and immune function. Omega-3s tend to favor anti-inflammatory signals, while omega-6s can promote inflammation if balanced in a way that’s too skewed. A deficiency can disrupt normal inflammatory responses, which may show up as more susceptibility to infections or lingering inflammatory symptoms.

• Hormonal balance. EFAs contribute to the production of signaling molecules like prostaglandins. When intake is too low, you can see subtle shifts in hormonal signaling—things like sleep patterns, energy regulation, and even stress responses.

• Skin and wound healing. Fatty acids help skin repair and maintain moisture. A shortage can slow healing and leave the skin feeling more fragile.

• Growth and development concerns in kids. For growing bodies, EFAs are part of healthy brain and visual development. Inadequate intake isn’t just a “might happen” scenario—it can impact development over time.

In short: a lack of EFAs isn’t merely a minor inconvenience. It can ripple through several systems at once, especially if the diet remains consistently low in these fats.

How much should you aim for, and where to find them

Dietary guidelines vary a bit, but the practical approach is straightforward if you’re aiming for balance and health.

• Omega-3s: Include fatty fish (like salmon, sardines, mackerel) a couple of times a week. For plant-based sources, flaxseeds, chia seeds, walnuts, and hemp seeds are excellent, especially as ALA. If you don’t eat fish, algae-based EPA/DHA supplements are a good option.

• Omega-6s: These come from many vegetable oils (like corn, sunflower, and safflower) and many nuts and seeds. They’re not the bad guys on their own; the key is balance with omega-3s.

• Ratios and daily targets. A common practical aim is to eat more omega-3-rich foods to improve the omega-6 to omega-3 balance. For those who track intake, a typical target is to consume enough EPA and DHA to reach roughly 250–500 mg per day, with higher amounts for certain life stages or health goals. Plant-based omega-3s are useful, but your body converts ALA to EPA/DHA only in limited amounts, so include direct EPA/DHA sources too when possible.

A quick shopping list for EFAs

• Fatty fish: salmon, sardines, herring, trout

• Plant-based sources: flaxseeds (ground), chia seeds, walnuts, hemp seeds

• Oils: extra-virgin olive oil (great for overall fat intake), flaxseed oil (not great for cooking heat), algae oil (for DHA/EPA)

• Fortified foods: some eggs or dairy products fortified with omega-3s

A note on supplements

Supplements can help, especially if your diet is limited or you have higher needs. Look for:

• EPA+DHA content per serving

• Freshness (check the expiration date; rancid fats taste off and aren’t good for you)

• Certifications (third-party testing can be a reassuring sign)

But food first, always. Whole foods come with a matrix of nutrients and fiber that supplements don’t fully replicate. And if you’re pregnant, nursing, or taking medications, check with a clinician before adding a high-dose supplement.

Practical ways to weave EFAs into daily life

• Start your day with a smoothie that includes flax or chia seeds, or top oatmeal with walnuts.

• Swap out some vegetable oils for fish-rich meals a couple of times weekly.

• Add a few spoonfuls of avocado or olive oil to salads or vegetables to keep meals tasty and fat-forward.

• If you’re plant-focused, plan algae-based DHA/EPA or consider fortified foods to ensure you’re not missing long-chain omega-3s.

• Store fats carefully. Light and heat degrade fats, especially susceptible oils like flaxseed oil. Keep them in the fridge and close to the source’s suggested storage guidelines.

Balancing omega-3 and omega-6: a simple mindset

The modern plate tends to be heavy in omega-6 because of common vegetable oils and processed foods. That’s not inherently bad, but it can tilt inflammatory signals if omega-3 intake is too low. The goal isn’t a perfect, obsession-worthy ratio; it’s a practical balance that supports your body’s needs. A few weekly portions of oily fish, plus plant-based omega-3s, usually does a good job of tipping the scales toward healthier signaling.

Common misconceptions worth clearing

• “All fats are bad”—not true. EFAs are essential, and fats in general are vital for energy, vitamin absorption, and cell function.

• “I eat a lot of oil, so I’m getting enough EFAs.” The type of fat matters. Not all fats are EFAs, and not all fats supply enough long-chain omega-3s EPA/DHA.

• “If I’m not deficient, I don’t need to worry.” Even without overt deficiency symptoms, optimizing EFA intake supports brain health, skin quality, and immune function over time.

The take-home message

If essential fatty acids aren’t present in your diet, the body won’t have the raw materials it needs to sustain critical functions. Deficiencies can show up in several areas—from mood and brain function to skin health and hormonal balance. The fix is straightforward: incorporate a mix of omega-3-rich foods (fatty fish, algae, flaxseeds, chia) and omega-6 sources in a way that supports a healthy balance. It’s not about chasing perfection; it’s about giving your body steady, reliable fuel that it can put to good use every day.

To make this as practical as possible, here’s a simple plan you can adapt:

• Two servings of fatty fish per week (or an equivalent algae-based DHA/EPA supplement).

• Daily plant-based omega-3 sources: a tablespoon of ground flaxseed in yogurt or smoothie, plus a small handful of walnuts.

• Use a chemistry-minded approach to cooking fats: low to moderate heat for delicate fats, higher heat for stable fats like olive oil in heat-appropriate ways.

• Check labels on packaged foods. Some products hide extra omega-6-rich oils in places you might not expect. If you’re aiming for balance, be mindful of hidden fats.

Let me explain with a quick scenario

Imagine your week stretches out with a few days of fish, a couple of plant-fat-rich meals, and some mindful snack choices like seeds and nuts. Suddenly, you’re not chasing a deficiency; you’re embracing a steady flow of EFAs that supports your cells, your brain, and your peace of mind. It’s not glamorous, but it’s deeply practical nutrition that compounds over time.

If you’re curious about the science, you’ll find that EFAs contribute to the fluidity of cell membranes—the tiny gates that control what gets in and out. They help your body manage inflammation in a controlled way, which is essential for healing, immune defense, and even the way nerves transmit signals. When those gates are well-furnished with fats, the ride through daily life feels smoother. That’s the core of why EFAs matter.

A final nudge

Nutrition is a long game. EFAs are a staple in that game, not a garnish. The right intake supports the body’s ongoing work—cell repair, hormone signaling, and a resilient immune system. If you’re building a plan for yourself or advising others, think of EFAs as one of the consistent, reliable elements that keep the body’s systems humming.

In short: don’t skip essential fatty acids. They can lead to deficiencies that ripple through mood, skin, immunity, and beyond. Feed your body a balanced mix of omega-3s and omega-6s from diverse sources, and you’ll be rewarding it with steadier energy, better skin, and healthier signaling—today and for the long haul. And that, honestly, makes the little daily choices worth it.