From a purely thermodynamic perspective, a calorie is just a calorie, and if you burn more calories than you consume, you will lose weight (which is why there's that guy who ate nothing but [fill in junk food here] and still dropped pounds; spoiler alert: he was still under-eating calories, even if they were junk calories).
While it'd be easy to run with this simplistic approach and blame those with weight problems on the fact that they are simply overeating, when we look beyond the lens of strictly weight loss....well, it's a little more complicated.
As we try to battle the so-called war on obesity, substantial evidence is emerging supporting the idea that the source of calories doesmatter, so much so that the type of food you consume can influence your metabolism and appetite control.
I recently read an editorial published in the British Medical Journal about the importance of a balanced omega-6 to omega-3 ratio in the prevention and management of obesity, and it really drove the point home that calories are not always just calories. I wanted to share its major points with you, especially because when we focus on weight loss in our practice, it's not just about numbers on a scale - it's also about promoting health. Quality of calories matters.
Omega-6 and omega-3 fats are types of polyunsaturated fats that are both crucial for health, but we're finding that the ratio of consumption (even though they're the same calorically) plays an important role in the management and treatment of overweight and obesity.
For example, high omega-6 intake increases white adipose tissue that is stored and it effects fat tissue development differently than omega-3s. Furthermore, (it's almost common knowledge now) too many omega-6s promote inflammation whereas omega-3s have the opposite effect. This is particularly important when we consider that the basis of many chronic diseases, including obesity, is a very pro-inflammatory state.
The table below, from the review, summarizes some of the differing effects of omega-6 and omega-3 fats on factors in obesity.
While I'm no proponent of the Paleo diet (or any diet, for that matter), there's no denying that, with increasing technology and industrialization, there's been some major changes to our food supply - even over just the last 100 years.
Modern agriculture helped to increase the production of vegetable oils high in omega-6s, as well as changed animal feed from grass to grain. Traditionally, animals grazed on grass containing omega-3s. Nowadays, most of our meat supply feasts on grain, corn, or soy, which is much higher in omega-6s. These factors ultimately led to a shift in our intake, disrupting the balance between omega-6 fats and omega-3 fats in the human diet. Check out the table below (from the same article) showing the ratios of omega-6 and omega-3 intake across different populations.
NOW, before you go crazy and start boycotting vegetable oils, grains, and meat, keep in mind that omega-6s are still very much necessary for health....what needs to change is the ratio of consumption of omega-6 fats to omega-3s. The typical Western diet currently sits at a ratio of 16:1 omega-6 to omega-3. The optimal for health?...More like something between 1-3:1.
A recent study, using data from the National Institutes of Health Women's Initiative study, showed the importance of maintaining a balanced omega-6 to 3 ratio in weight loss. Over a 10-year period, they were able to show that high concentrations of omega-6 fatty acids in the membranes of red blood cells (indicating a high consumption) led to an increased risk of weight gain, as well as did a high ratio. Conversely, women whose red blood cell membranes had a higher concentration of omega-3s had a decreased risk. This study is hugely impactful because they actually measured the concentration of fat in the blood rather than using a typical diet recall (which can be riddled with errors and inaccuracies).
OK, so data and information are all well and good, but let's talk about what truly matters: the HOW. If you want to combat overweight and obesity, or even just promote long-term health, what should your diet look like?
The first goal is to decrease intake of omega-6 fats so we can get that ratio down from 16:1!
Vegetable oils (sunflower, corn, safflower, cottonseed, soybean) are one of the major sources of omega-3 fatty acids in American diets because they are so predominant in packaged foods. Read almost any ingredient label, and you're likely to find at least one of those listed every time. You could either be very diligent about reading labels and finding products without these oils (good luck), or take the (probably) easier route and switch to a more whole foods based diet. This doesn't mean warding off packaged foods forever (convenience is awesome, we know!), but it does mean cooking a little more at home, packing snacks from home, and buying fresh, whole ingredients (grains, fruits, vegetables, beans).
Secondly, INCREASE your intake of omega-3 fats.
Cold-water, fatty fish are typically high in omega-3s. Try incorporating salmon, halibut, sole, herring, anchovies, bluefish, sardines, sturgeon, lake trout, or tuna (although, you should limit tuna consumption to once every few weeks due to mercury concerns) at least 2-3 times per week to boost your intake.
You can also incorporate nuts and seeds that are high in omega-3s, such as walnuts/walnut oil, flaxseeds/flax oil, chia seeds, hemp hearts, canola oil, and pumpkin seeds.
As mentioned previously, a major source of omega-6 comes from the meat and dairy we consume. When animals are predominantly fed grain, corn, or soy, the product you consume is higher in omega-6. On the other hand, animals raised on grass/pasture provide more omega-3s. That means, when available and affordable, select grass-fed and pasture-raised meats and dairy products.
Set a few goals to change your intake and go for it! Got questions? Work with us.