Scientific Truths About Diet and Health
Updated: Nov 11
No scientific truism is beyond all scrutiny and error. And yet, to the best of our current knowledge, we do have a scientific consensus on many things. Health and fitness science has a few of these so-called ‘certainties’ but is otherwise filled with falsehoods and unproven theories. And don’t even get me started on nutritional science. According to the Mayo Clinic and many other reputable institutions, nutritional science is borderline ‘pseudoscience’. The majority of nutritional research is epidemiological (correlative and not causative in scope) with an emphasis on notoriously inaccurate dietary recall journals and outcomes that cannot be replicated. There are very few randomized placebo controlled double blind studies in the field of human nutrition. This opens the field up to conjecture and contradictions. In fact, many studies show statistically significant opposing outcomes. This is why one week you will read “Eggs Will Kill You” and the next week you will hear “Eggs Will Help You Live to 100″. What to believe? The list below covers some of the important fundamental ‘truths’ of exercise and diet:
Eating more calories than you burn will result in weight gain. There are many factors that influence weight gain beyond calories – but in the end, it is an excess of calories (one way or another) that will add the extra pounds of flub.
Science has not identified the healthiest way to eat. Let me be clear: There is no one best diet plan. It is quite definitive that humans are able to thrive equally well on a variety of diets (even vegan, keto, high carbohydrate and super high-fat diets). The law of individual differences is something we should have all learned in kindergarten. Furthermore, the notion that some diets or exercise regimes are better than others is not based on sound science. If you find something that works for you, stick with that.
Most diets work in the short term but not long term. Weight loss is typically attained through lifelong nutritional transformations, behavior modifications, and psycho-social changes. There are no quick fixes to long term body composition problems.
Exercise temporarily boosts cognition, decreases stress, improves your heart health and helps ward off disease. It is not clear which type of exercise is best. Yet, according to the ‘Blue Zone‘ research (places on earth where the local population typically lives to 90-100 years old) people in these areas naturally move a lot during the day but don’t necessarily follow an exercise program. What is unambiguous, is immobility. Being sedentary is clearly unhealthy.
Resistance training and impact based cardio (running, jumping, walking etc) will build stronger bones – see Wolf’s law. If you have a risk factor for osteoporosis or are an astronaut you better participate in some form of resistance or axial load training.
The principle of exercise specificity states that if you want to get better at something (physically) then you must do that something. If your goal is to run a 6-minute mile you must practice running. This falls in line nicely with the SAID principle (specific adaptations on imposed demands). If you want to be faster train fast. If you want to be strong, then you must train for strength. Your body adapts to the thing you are doing. If you are training to finish a marathon in under 3 hours you don’t spend your time honing your bowling game.
All humans need water to live – through not 8 glasses per day for everyone. The amount of water you need daily will vary due to a multitude of factors including; body size and temperature, dietary intake, hormonal balance, illness/disease, exercise, environmental conditions and pregnancy/breastfeeding.
You cannot live without salt. It is essential to health. Your body can’t make it, and your cells need it to function. But don’t worry, you are unlikely to eat too little.
We sit too much and move too little. This is a major contributing factor to our obesity epidemic and the lower back pain issues facing 1st world populations.
Humans are omnivores and have always eaten whatever they could find. With a few exceptions, the plants and animals our great ancestors ate are no longer available. Virtually all the food we consume today has been engineered through a variety of methods in order to maximize yields, increase palpability and have a longer shelf life. Evidence tells us to eat a variety of foods in moderation.
Most people do not need to take dietary vitamin/mineral supplements if they are following a balanced diet. Yes, there are often special situations, such as pregnancy, disease, illness or the taking of certain medications where special nutritional supplementation needs arise. However, no dietary supplement has ever been proven to extend lives, make you smarter or prevent disease. In fact, there is emerging evidence that some vitamins and minerals may increase mortality and/or can become toxic (like mega-doses of vitamin A or D). On the other hand, there is strong peer-reviewed research backing the health benefits of garlic, fish oils, niacin and zinc supplements.
Eating lots of non-starchy vegetables seems to be healthy for most. Vegetables are perhaps the most nutritious food you can eat. They are packed with wholesome life sustaining nutrients like fiber, vitamins, minerals, water and even some plant based protein.
Fructose is not toxic in ‘normal use’ amounts. It is processed mainly by the cells in the liver. Glucose can be processed by every cell in the body. Eating exceptionally large amounts of fructose taxes the liver, leaving less time to break down fat. This in itself does not prove fructose is evil. Yet there is overwhelming evidence supporting the fact that energy-dense foods (highly sugared) have little nutritional value and are unhealthy.
The obesity epidemic is multifactorial in nature and can’t be blamed on one element alone. Obese individuals do not, as a whole, have less willpower than skinny people. The feeling of hunger is triggered by over 100 physiological, psychological and environmental factors – this is different for each person. Don’t fat shame.
The standard American diet (SAD) is not healthy. The SAD includes tons of packaged foods, sugar, processed meats and liquid calories. It is deficient in fiber, vegetables, and fruit. Most of us wouldn’t even subject our dogs to McDonald’s and Coke – yet we consume that stuff every day.
Protein has the largest thermic effect of food (TEF) of any macro-nutrient. This means it takes more calories to digest protein than fat or carbohydrates (up to 30%). For example, when you eat 100 calories of chicken your body may use 30 calories to digest it. Highly processed foods like Twinkies have a very low TEF. Your body does not let a calorie of Oreos or Pepsi Cola go to waste- just to your hips.
We need protein and fat to live. We do not need carbohydrates (although I wouldn’t recommend a zero carb diet). All we need to sustain life