Many foods are packaged with accompanying nutritional information written on the packaging. It may be read and taken at face value. However many factors determine your true gains of nutrients.
Recognize that farming conditions can alter a plants level of nutrients! A seasons harvest can have different nutritional levels to another seasons harvest. While we receive our nutrients from plants or other foods, all foods receive their nutrients from the soil or sea; which receive their nutrients from rocks. There is more to a rock or stone than meets the eye, as these hold nutrients! By the processes of erosion there is minute chipping away to permit release of nutrients. The released nutrients can then be taken up by the surrounding sea or ground.
Any garden is improved by the presence of stones. Constant planting and taking from the ground does deplete our soils. To compensate we need to give back. A plant to be packaged or taken to any store can not demand to have a certain level of nutrients, as the packet or box said it will have it! Plants only take what is available.
Climates affect plants and when growing in different climates the same type of plants have different nutrient content. Needs alter according to where we live and the climate affects nutritional needs. Note when you read the nutritional information of two similar foods, as information on various brands can be provided by different sources. On any day if we all ate exactly the same level of nutrients, our absorption tends to differ. Stress tends to lower rates of nutrient absorption and retention of nutrients.
Anyone may consult with a relevant health professional to asses whether or not they are receiving levels of nutrients to match their needs. True, nutritional charts are extremely beneficial and essential to work out how to help anyone to be healthy! What we should realize is that we can not bet on that fixed numerical number and our bodies do not absorb the same percentage always. Generally we absorb more if we need it, but sometimes other factors disrupt this; such as alcoholism, certain drugs and digestive-related disruptions.
Nutritional guidelines can sway choices along a healthy way. Do not worry about the extra calorie to the detriment of better mineral levels in foods. Watch of calorie content should not accompany dismissal of the levels of minerals and vitamins. Use whole foods to be on a more nutritious path to lead to health. Indeed a little of nutritious fatty nuts may support some people to lose weight, as we need minerals and vitamins to actually burn calories. We will always need minerals and vitamins; have a balanced view and intake of nutrients.