Subject: International Society of Sports Nutrition position stand: diets for body weight reduction
What this means
No diet type is clearly superior; what counts is the deficit, with resistance training and sufficient protein (for the general population 1.2-1.6 g per kg body weight per day) to preserve lean mass.
A · High confidence. Multiple consistent meta-analyses or a position stand. Sufficient basis for a fixed choice in the coaching.
The International Society of Sports Nutrition sets out in 15 points what the literature says about diets for weight loss in adults who are generally healthy, physically active or athletic. Very-low-energy (<800 kcal/day) and low-energy diets (800-1200 kcal/day) produce greater short-term weight loss, but no long-term advantage over less aggressive energy restriction, and may increase lean mass loss. Intermittent fasting does not differ from continuous energy restriction. The carbohydrate-fat proportion can be chosen by preference; ketogenic diets tend to decrease fat-free mass more. The ISSN calls resistance training and sufficient protein indispensable for preserving lean mass, regardless of diet type. For the general population it considers 1.2-1.6 g protein per kg body weight per day appropriate.
Adults who are generally healthy, physically active or athletic. The abstract gives no separate recommendations for people aged 40 to 70.
Position in 15 points, approved by the ISSN Research Committee; the abstract reports no number of studies.
This is an expert judgement of the literature, not new research. The higher protein ranges (1.6-2.2 and 1.9-3.2 g per kg) apply to people doing resistance training, the highest to lean trained people in an energy deficit.
The library held the 2017 position stand; this successor confirms that no diet type is universally superior and adds a protein recommendation per kg body weight for the general population. For REZA the order stays the same: a deficit that can be sustained, continued resistance training and sufficient daily protein. Which diet someone uses for that depends on preference and what is feasible. With medication or a medical condition, a diet with a large deficit belongs with the GP or dietitian.
Position stand
A position stand is a critical analysis of the literature by a professional society, not a systematic review with meta-analysis; the abstract reports no search method, number of studies or effect sizes. It covers healthy, active and athletic adults and draws on clinical research in people with overweight where relevant. Dehydration-based weight cutting, pharmacotherapy (GLP-1 receptor agonists) and bariatric surgery are outside its scope.
This information is general education about scientific research. It is not personal medical advice and does not replace diagnosis or treatment by a doctor or other healthcare professional. If you have symptoms, a medical condition or take medication, consult your GP or treating professional before changing your training or nutrition.
