There are three types of nutrients that the body uses for daily function and energy: carbohydrates, fats and protein. These are also referred to as macronutrients (“macros”). There are many diets that can be adopted to achieve different health goals. However, not all foods, calories and nutrients are created equal. Specific foods impact each process in the body and can cause a drastic difference in desired results.
In general, when attempting to lose, maintain, or gain weight, a caloric deficit, stasis, or surplus must be maintained, respectively. A general rule of thumb is to consume the number of grams of protein as the number of pounds you weigh. For example, if you weigh 150 lbs, you should consume 150 g of protein throughout the day. The remaining calories per day are made up of carbohydrates and fats.
For people focused on trying to lose weight, there is a common debate over what composition of carbohydrates and fats is most effective. It is intuitive to assume that in order to lose body fat, one should limit their intake of higher fat foods. Recently however, diets characterized on reducing carbohydrate intake while incorporating foods with more fats have been reported to offer more long-lasting results.
Carbohydrates contain 4 calories per gram, the same amount as protein.
- Simple (aka sugars): sucrose (white sugar), fructose (fruit sugar), lactose (milk sugar)
- Complex: unrefined (brown rice, whole grains), refined (white rice, white flour)
- Fibrous: vegetables (broccoli, celery, etc.)
Carbohydrates are also labeled according to their glycemic index (GI) which refers to how they contribute to blood sugar levels. Carbohydrates with low GI values are usually complex and/or fibrous, while simple carbohydrates have higher GI values.
More simply, “bad carbs” = simple carbs (processed foods like white bread and candy that contribute to higher blood sugar levels) and “good carbs” = complex and fibrous carbohydrate sources (whole grains and vegetables that contain vitamins and contribute to feeling full).
Positive Health Benefits
- Regulate cholesterol levels
- Support muscle growth (with exercise)
- Complex and fibrous carbs contribute to feeling full for longer periods of time
- Feelings of higher energy after consumption
Negative Health Impacts
- Can contribute to increased blood sugar and diabetes
- Excess is converted by the body and stored as fat
- “Crash” after initial energy spike or feelings of sluggishness with overconsumption
- Contribute to water retention (so cutting them may lead to initial weight loss, but it is mostly water weight)
Fats have 9 calories per gram and are the most calorically dense nutrient category.
- Unsaturated: monounsaturated (avocado, nuts) or polyunsaturated (vegetable oil, omega-3 fatty acids)
- Saturated (red meats, coconut oil, butter)
- Trans (processed foods, margarine, shortening, chips)
Generally, unsaturated fats are considered “good fats” while saturated fats should be limited and trans fats should always be avoided (aka “bad fats).
Positive Health Benefits
- Necessary for the absorption of certain vitamins
- Consumed by brain and heart functions
- Support regeneration of healthy hair and nails
- Contributes to feeling full for longer periods of time
Negative Health Impacts
- Trans-fats negatively affect blood cholesterol levels, contributing to heart issues
- Contribute to weight gain if eaten in excess
The Atkins Diet was popularized in the early 2000’s by celebrities and others and consists of four phases. In Phase 1, less than 20 grams of carbs are consumed per day. This is done by limiting consumption of foods like sweets, breads, rice, potatoes, etc. Phase 1 is intended to initiate weight loss.
Carbs are slowly added back into the diet in Phases 2 and 3. Phase 4 is maintenance, where a steady and low level of carbs are consumed in order to remain at the goal weight. However, after a quick rise in popularity, the company declared bankruptcy the Atkins Diet</a> as the fad diet went out of fashion.
More recently, a regimen known as the “Keto Diet” (short for ketogenic) has gained popularity. It is defined as a low-carb, high-fat diet. The Atkins Diet is a type of ketogenic diet but had different requirements. The modern Keto Diet is defined as an intake of 60 percent fat, 35 percent protein and 5 percent carbohydrates.
This is meant to transition the body into relying on fats as the main source of energy. This will occur after a period of being deprived of carbohydrates, when the liver breaks down fats (from one’s own fat stores as well as dietary intake) into fatty acids and ketones.
The ketones are consumed to generate energy. There are many reported benefits of this low-carb, high-fat diet. By reducing carbohydrate consumption, blood sugar levels are usually stabilized (fewer spikes).
Higher levels of body fat are burned due to the re-conditioning of metabolic processes. Ketones can also be consumed by the brain, offering improved mental performance. Detractors of ketogenic diets report that forcing the body into this state can be harmful in the long run and that weight loss is temporary but will be regained if a less restrictive diet is reapplied.
Although consumers have been warned against the consumption of fats for decades, they are a necessary part of everyday diet. The myth that “fat free” foods or low-fat diets are a healthier choice is not always true. These foods tend to use targeted advertising while masking high sugar content or artificial ingredients.
Carbs from sources like sodas and chips can contribute to weight gain and disease. Fats from sources like avocados and omega-3’s (fish) can improve nutrient absorption and brain function.
Comparing fats and carbohydrates is kind of like comparing apples and oranges, an unrealistic evaluation. It is more valuable to understand that a “balanced diet” is necessary in order to to lose weight or improve overall health. A balanced diet includes foods that contain a mix of carbohydrates, fats and protein. “bad carbs” and When considering carbs and fats, remember that both are necessary for regular bodily function and to choose sources of “good carbs” over “good fats” over “bad fats” for an apples to apples evaluation.
Depending on genetics, exercise regimen and weight loss goals, different people will require different amounts of these nutrients. When choosing a diet plan, it is important to educate oneself of the potential side effects and possibly consult a professional. Recent scientific advances into genetic sequencing have allowed researchers to better define what type of diet best suits an individual based on their ancestors’ consumption patterns.
Some people will thrive on high-fat while others will thrive on high-carb due to genetic differences, even if they have the same lifestyle. When considering all of this as well as new research over time, be wary of food fads and myths.