5 min read

Complete Nutrition vs. Fad Diets

By Nora Minno, RD

We’re all looking for ways to improve our health. As a dietitian I have gotten questions about every single fad diet out there – “does it work” “should I try it?” I could go on and on. Time and time again my answer remains – focus on complete, balanced nutrition from a plant-forward or plant-based diet. Focusing on consuming an abundance of nutrients from quality sources, such as plants, is an evidence-based way to build sustainable healthy dietary patterns that last and to ensure your body is getting enough of what it needs to stay healthy.

And while nutrition can be incredibly complex scientifically speaking, getting adequate, balanced nutrition does not have to be complicated, and it does not need to cost a lot of time or money. Complete nutrition can actually be quite simple if you know what to look for in the right products. 

What is Complete Nutrition?

What is Complete Nutrition?

Simply put, complete nutrition refers to a diet which contains adequate amounts of calories, macronutrients, and micronutrients to meet an individuals’ needs. Typically, we look at this over the course of a 24-hour period. 

When talking about a single product, like a drink or a bar, something that is considered “nutritionally complete” means that it could be used as a sole source of nutrition because it could provide all of the calories, macronutrients (protein, carbohydrates, and fat), vitamins, and minerals an individual would need to support their body’s needs. For example, Soylent drinks and powders are considered nutritionally complete because they contain all of the essential macronutrients and micronutrients recommended by health authorities in one source.

What Makes Nutrition Complete?

Soylent Complete Meal Shakes

Exact nutritional needs – including calorie and fluid needs – can vary based on the individual and are influenced by several factors including age, sex, activity level, and medical conditions.

There are, however, general guidelines set forth by health authorities that help us understand what complete nutrition means and what most individuals need to stay healthy.


Simply put, calories are a measurement of energy – so the more energy someone requires, the more calories they need. Calorie needs are based on several different factors including age, gender, activity level, body composition, and medical conditions. We obtain calories by consuming macronutrients. 



There are 3 essential macronutrients – Fat, Carbohydrates, and Protein. These are the “big” (hence “macro”) nutrients that contribute to the calorie content of different foods and beverages. 

The Institute of Medicine has calculated guidelines for proportions of macronutrients that would meet the nutritional needs of most individuals following a standard diet1.

Carbohydrates: 45-65% of energy
Protein: 10%-35% of energy
Fat: 20%-35% of energy

So based on a 2,000 calorie per day diet, this would look like:
Carbohydrates: 225-325g per day
Protein: 50-175g per day
Fat: 44-77g per day

As you can see, these ranges are quite wide an intended to be broad enough to cover the macronutrient needs of most individuals. Calculating more specific recommendations for carbohydrates and protein can be done using a g/kg body weight formula and taking into account activity levels. 

Carbohydrates: 5-12 g/kg body weight
Protein: 1.2-1.8g/kg body weight

Within the 3 macronutrient groups are important subgroups: fiber under carbohydrates and essential fatty acids also known as linoleic acid  (a polyunsaturated omega-6 fatty acid) and alpha linoleic acid (a polyunsaturated omega-3 fatty acid) under fats.


Micronutrients refer to vitamins and minerals that are vital for health and disease prevention. 

In the United States, the Institute of Medicine established principles and guidelines for adequate dietary intake, known as Dietary Reference Intakes or DRIs. DRI is the general term for different reference values that set to help plan and assess nutrient intakes of “healthy people”2

There are DRIs for 14 vitamins (A, C, D, E, and K, and the B vitamins: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxal (B6), cobalamin (B12), biotin, and folate/folic acid), and choline3,4 and 15 essential minerals (calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, iodine, sulfur, cobalt, copper, fluoride, manganese, and selenium5.

How to Achieve "Complete" Nutrition 

While it’s important to pay attention to the amount of calories, macronutrients, and micronutrients one needs – it’s also important to pay attention to the source of those nutrients.

Let’s take a look at macronutrient sources.


Poly & Mono Unsaturated Fats: There are two main different types of fat, saturated and unsaturated. Consuming quality poly- and mono- unsaturated fats from quality sources, like plant-based oils, can help support brain health, heart health, and cellular function. 


Low-Glycemic Carbohydrates: The glycemic index of foods is a way to measure how much that food boosts blood sugar. The lower the glycemic index, the lower the effect on blood sugar, while the higher the glycemic index, the higher the effect on blood sugar. Choosing lower glycemic sources of carbohydrates can support a healthy blood sugar, help manage hunger between meals, and may even lower one’s risk for other chronic diseases like diabetes and heart disease6.


Complete Proteins: Proteins are made up of amino acids, which are often refer to as the “building blocks of life” since they support so many critical functions in the body. There are about 21 amino acids in total, 9 of which are considered “essential” meaning they must be obtained through the diet, your body cannot produce them. When a protein is “complete”, that means it contains adequate amounts of all 9 essential amino acids. You can ensure you’re consuming complete proteins by choosing a complete single source, such as soy protein, or by combining a variety of foods to ensure consumption of all 9 essential amino acids. It’s important to note that soy is one of the only complete plant-based proteins, and other plant-based proteins such as pea and rice would not be considered complete because don’t contain all essential amino acids.

Soylent Drink Strawberry

The most important thing to remember when building a complete nutrition routine is variety. Our bodies love variety. And while some foods and supplements could be considered a sole-source of nutrition, switching it up helps us build a healthy gut biome and ensures that we are getting a variety of phytonutrients from plants.

So whether using Soylent Complete Meal Shake or Powder to help you reach your protein, vitamin, and mineral needs between meals – continuing to seek balance and variety in your diet will be key.