Calorie Deficit and Diets Explained
July 12, 2024
Energy in… energy out… seems simple right? Clearly it’s not that simple, or we wouldn’t be here trying to work it out! But it doesn’t have to be made to be as confusing as it is. “Diets” that are successful will be due to the fact that the individual was in a calorie deficit (less calories IN than OUT). If this isn’t the case, fat loss will not occur. It’s important to understand that there is no one method that is best for all situations or individuals. Mostly this is because of a particular body composition, age, gender, activity levels and other unique features that make you… YOU!
Some people will see positive results from an increase in one macronutrient (fat, protein, carbohydrate) over another dependent entirely on the body composition of the individual, activity levels, age, gender, etc. Let’s explore a brief overview of the most common macronutrient diets. What does it REALLY mean to be low or high in a particular nutrient in your plan.
Low-Energy (calorie) Diet (or LED/VLED) - 1200kcal per day on average or less (mix of macro)
This diet is beneficial for obese individuals where health markers are the most important concern. Even then, it’s advised that the longterm use of this level of deficit be limited. This type of diet is very restrictive and has numerous negative effects - so much so that it should be followed under the supervision of a medical professional. Among the negative effects are lean body mass loss, poor athletic performance, lengthy recovery time from basic injury or athletics, and nutrient and micronutrient deficiency. The more serious are adverse effects on the metabolic rate and disruptions in the functioning of the thyroid gland.
Low-Fat Diet - Fat intake is 20% or less of the daily total calorie intake
The misconception is that “Fat makes you Fat” - while that has some truth to it in theory, it’s not truly the story. When we reduce the percentage of fat in our diet, sure, we create a calorie deficit (fat grams provide the body with 9 kcals each) but our body requires fat for numerous functions such as cellular function, hormone production (ahem… peri/meno ladies, and sex hormones such as testosterone…), absorbtion of fat-soluble vitamins and fatty acid intake. When we cut out enough of this source of energy, we risk essential fatty acid deficiency, find increased in triglyceride levels and limit sources of good foods with good health implications (nuts, seeds, oils).
Low-Carbohydrate Diet - Carbohydrate intake is 20-40% (study dependent) or less of total calories
While this diet has shown beneficial for body fat reduction, when analyzed in studies when calories are matched in a higher carbohydrate level diet, there is not a superior fat-loss benefit. When the overall calorie intake is the same, the fat vs carbohydrate percentages have no benefit over the other in a 12 month period. A lower carbohydrate diet can help reduce intake from highly processed, hyperpalatable foods that have lots of excess sugar. Due to the energy contribution carbohydrates provide our movement and exercises, low-carb diets also make athletic performance subpar and interfere with brain function and overall mood.
For those of us who have heard that low-carb is the best way to lose weight, I’m sorry but it’s just not true. When examining short and long-term studies, when calories remain the constant in a low- or high-carbohydrate level, the weight (fat) loss implications have no benefit over the other. Same with low-carbohydrate vs low-fat diets. So yes, a low-carbohydrate diet can help avoid many highly processed items, but if an individual is enjoying a wide range of of healthier options of carbohydrates available to them, they will generally enjoy better menu availability, access to wider micronutrients, better athletic performance, sleep, brain function, and long term weight control.
High-Protein Diet - Protein calories make up of more than 25% of total intake
There is strong evidence showing multiple health and composition benefits to consuming a range of .5-1g of protein per pound of bodyweight. This diet does well to preserve fat-free mass (lean muscle mass) and increase satiety and tend to result in more body-fat reduction when compared to low-protein diets. Lean and active resistance training individuals in a calorie deficit can sometimes need more (1-1.5g/lb). Research strongly shows evidence consuming proten evenly through the day is more beneficial to absorption rates. High protein diets can come with a price-tag - both literally and physically! Protein costs are high for quality supplements when an individual cannot consume enough through a whole foods diet. These protein powders and bars have come a long way recently in that they can be mixed in any variety of recipes or taken alone. But not all whey is created the same - quality can wildly vary. Some individuals who feel that they might need a vegan formula if they feel unwell taking whey might find that it’s simply the quality of the protein. Higher protein diets help with increased satiety and therefore can be useful for reducing calorie intake. And back to quality protein: higher animal protein intake does increase fat consumption and a risk of associated health risks. Choose protein sources as minimally processed as possible like eggs, dairy, vegetables, legumes and lean cuts of meat.
*FACT vs FICTION*
There are some dangers with a high-protein diet for individuals who have existing kidney disorders. However, the concern regarding high-protein intake being dangerous to kidney or liver health is simply unfounded. There is no strong evidence that heathy individuals with a high to very high intake are at risk.
In the end, the best way to fat loss and keeping it off is to consume calories in a deficit until maintenance is required. In studies of 12-24 months, healthy and active individuals who strength train 2-4x weekly consumed a consistent deficit between 10-15% achieved better results (lean muscle mass retention, fat loss, body fat % and athletic performance) than their counterparts who reduced 20-30%. In the case of longterm results and retention, less isn’t always more! When I work with clients, we play the long game - fat losses will be greater at some stages than others, lean muscle mass loss is an indicator of concern, and plateaus are inevitable. If the scale isn’t moving, there’s often a culprit - but patience and some real evaluation of behaviors, lifestyle, and portion control can often put us back on track!
While I am an advocate for quality supplementation, there’s no better fuel that whole foods, water and sunshine!
Be Fit & Well!
Casey
References:
Ryttig et al., 1997';,Leeds,2014; Ryan & Yockey, 2017; Katz, 2005; Yumuk, 2015; Renzella et al., 2018; Sofi et al., 2014; Filippatos et al., 2016; Eposito et al., 2011; Guess, 2018; Schwingshackl et al., 2018; NASM 2024; Mansueto et al., 2014