February 13, 2020

The XDL Diet is a short-term, calorie reduction, high protein, moderate fat, low carb diet that includes a scheduled carb spike (Hale, 2005). The diet also provides suggestions for manipulating water, potassium, and sodium intake. The diet is used when rapid weight loss is the objective (e.g. athletes need make weight, photo shoots, beach vacations, surgery etc.). Very low calories are ingested, 40-50% below maintenance level, for 6-7 days. The last 2-3 days of the diet the involve water, potassium and sodium manipulation. There are other diets similar to this diet. The XDL Diet is not a magic formula.

You can expect rapid weight loss when following the diet. To my knowledge the greatest amount of weight lost while following the diet is 28lbs. Exceptionally lean people (under 6%) have lost up to 12lbs while following the XDL Diet. Weight consists of various components- all of the weight loss is not body fat.  The majority of weight loss will not be due to loss of subcutaneous fat.

Subcutaneous fat is the fat under the skin; the type of fat  most people think of when we talk about body fat. Men typically store most of their subcutaneous fat around the midsection and upper back; women typically store the majority of subcutaneous fat in their hips and thighs.

hat about hard to lose fat areas (a.k.a stubborn fat)? So called stubborn fat is subcutaneous fat, that is generally the first place where fat accumulates and the last place it leaves when dropping body fat. For men, hard to lose areas, as indicated above, are midsection and upper back, and for women, it’s hip and thigh fat. Research indicates that certain fat deposits are physiologically different in terms of how they respond to lipolytic (fat breakdown) processes. They also have poor blood flow when energy reserves are being mobilized in an effort to provide substrates for energy. There is research regarding hard to lose fat; this research emphasizes blood flow specifics and adrenergic receptors characteristics.

Body Composition

Body composition can be assessed at different levels. The five level approach provides a  guide—atomic, molecular, cellular, tissue, and whole-body.

Atomic level

Basic chemical elements compose the atomic level. There are approximately fifty elements found in the human body. Oxygen, carbon, hydrogen, and nitrogen account for approximately 95 percent of body mass, and the addition of seven other elements (sodium, potassium, phosphorous, chloride, calcium, magnesium, and sulfur) account for approximately 99.5 percent of body mass.

Molecular level

The molecular level of body composition focuses on four of five components—water, lipid (fat), protein, minerals, and carbohydrates. Due to the small storage capacity of carbohydrates, it isn’t usually considered in estimates of body composition.

Cellular level

Body composition at the cellular level is composed of cells and substances outside of the cells. Extracellular fluids and extracellular solids compose the substance outside of cells. The primary extracellular fluids are bone minerals and other components of connective tissues.

Tissue level

At the tissue level, the study of body composition focuses on the contribution of specific tissues to body mass—skeletal muscle, adipose tissue, bone, blood, viscera, and brain.

Whole-body level

The whole-body level of body composition refers to it’s size, shape, physique, and proportions.

XDL Diet Guidelines

In the book- XDL Diet (2005)- three levels are discussed: 1) General fitness 2) Competitive athletes 3) Bodybuilding (also other physique related competitors). It is important to focus on preparation phase- the phase occurring before you start the diet. Prepare your foods in advance; design your eating plan, specifically, while in preparation phase. The menu should be written and placed in an area where access to menu is easy. Purchase a food scale, and purchase a calorie book or locate a website that lists food cals…and nutrient profiles. It is important to have at least a relatively accurate knowledge of your body fat percentage and activity level; these factors are important when setting up diet specifics. Common mistakes during prep phase: not preparing food in advance, failing to prepare menu before starting diet, not having access to a food scale, calorie underestimation, waiting until day 1 of diet before grocery shopping and making food substitutions that are inappropriate. Food charts and supplement recommendations are included in the book. Supplements suggested include protein powder, fish oil, vitamin C, multi-vitamin mineral and potassium (other supplements may be used in some situations). The book provides sample eating plans and calculation processes for each level of the diet. Level 3 is the highest level and requires stricter strategies than the other 2 levels. The drying out process begins on day 5, and continues for the remainder of the diet. Drying out is an attempt to rid extracellular fluid while preserving intracellular skeletal muscle tissue fluid. The process involves further changes in eating, Vitamin C supplement, Potassium supplement, water (including distilled water) and sodium manipulation (including sodium in food).

XDL Diet Modifications. The central principles of the diet are the same as they were when the diet was originally constructed. However, there are some changes regarding food selection and the drying out process. Regarding low and high glycemic index carbs, in the current diet a wider range of foods can be eaten. The drying out process does not require drinking massive amount of water prior to cutting water intake. The supplement recommendations are almost the same as they were with the original- a few other options are suggested. Training recommendations vary depends on multiple factors.

The diet works well for physique purposes. But does it work for general fitness enthusiasts and athletes who compete in other sports? It depends on the individual. In general, the guidelines are too strict for general fitness enthusiasts. And, some athletes notice a decrease in performance when following the XDL Diet. The diet was not created to enhance athletic or cognitive performance; it isn’t for long-term weight maintenance or weight loss. I have seen more than a few people follow the XDL Diet and lose lots of weight only to rebound and gain more weight than they lost. I generally recommend sedentary individuals or recreational exercisers take a moderate approach to weight loss. Long term weight loss is best served using principles of cognitive behavioral nutrition.

Cognitive Behavioral Nutrition: The New Paradigm

Cognitive Behavioral Nutrition: In the Lab

Seth Cairns- Post XDL Diet

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