This secondary analysis examined the influence of changes in physical activity (PA), sedentary time and energy expenditure (EE) during dietary energy restriction on the rate of weight loss (WL) and 1-year follow-up weight change in women with overweight/obesity. Measurements of body weight and composition (air displacement plethysmography), RMR (indirect calorimetry), total daily EE (TDEE) and activity EE (AEE), minutes of PA and sedentary time (PA monitor) were taken at baseline, after 2 weeks, after ≥5 % WL or 12 weeks of continuous (25 % daily energy deficit) or intermittent (75 % daily energy deficit alternated with ad libitum day) energy restriction, and at 1-year post-WL. The rate of WL was calculated as total %WL/number of dieting weeks. Data from both groups were combined for analyses. Thirty-seven participants (aged 35 (sd 10) years; BMI = 29·1 (sd 2·3) kg/m2) completed the intervention (WL = –5·9 (sd 1·6) %) and 18 returned at 1-year post-WL (weight change=+4·5 (sd 5·2) %). Changes in sedentary time at 2 weeks were associated with the rate of WL during energy restriction (r = –0·38; P = 0·03). Changes in total (r = 0·54; P < 0·01), light (r = 0·43; P = 0·01) and moderate-to-vigorous PA (r = 0·55; P < 0·01), sedentary time (r = –0·52; P < 0·01), steps per d (r = 0·39; P = 0·02), TDEE (r = 0·46; P < 0·01) and AEE (r = 0·51; P < 0·01) during energy restriction were associated with the rate of WL. Changes in total (r = –0·50; P = 0·04) and moderate-to-vigorous PA (r = –0·61; P = 0·01) between post-WL and follow-up were associated with 1-year weight change (r = –0·51; P = 0·04). These findings highlight that PA and sedentary time could act as modifiable behavioural targets to promote better weight outcomes during dietary energy restriction and/or weight maintenance.

Obesity is associated with an increased risk of various diseases and mortality. Although nearly 50 % of adults have been reported trying to lose weight, the prevalence of obesity has increased. One factor that hinders weight loss-induced decrease in obesity prevalence is weight regain. Although behavioural, psychological and physiological factors associated with weight regain have been reviewed, the information regarding the relationship between weight regain and genetics has not been previously summarised. In this paper, we comprehensively review the association between genetic polymorphisms and weight regain in adults and children with obesity after weight loss. Based on this information, identification of genetic polymorphism in patients who undergo weight loss intervention might be used to estimate their risks of weight regain. Additionally, the genetic-based risk estimation may be used as a guide for physicians and dietitians to provide each of their patients with the most appropriate strategies for weight loss and weight maintenance.

Weight loss maintenance is crucial for obesity management, yet optimal dietary patterns for this period are not established. We aimed to explore the relationship between adherence to the Mediterranean diet and weight loss maintenance. Sample includes 565 adults (62 % women) of the MedWeight study. Eligible volunteers were those reporting intentional weight loss of ≥10 %, starting from a BMI ≥ 25 kg/m2, over 12 months prior to enrolment. Based on current weight, participants were characterised as maintainers (≤90 % maximum weight) or regainers (>95 % maximum weight). Socio-demographics and weight history were recorded. Dietary intake was assessed by two non-consecutive 24-h recalls within 10 d and analysed in energy, macronutrient and food group intakes. Adherence to the Mediterranean diet was assessed with the Mediterranean Diet Score (MedDietScore) (range 0–55, greater scores showing higher adherence). Protein intake was higher in maintainers than in regainers (P < 0·001). When MedDietScore quartiles were considered, a linear trend for weight loss maintenance was revealed (P < 0·05). After adjustment for basic demographic characteristics, being in the third or fourth quartile of the MedDietScore (v. first) was associated with 2·30 (95 % CI 1·29, 4·09) and 1·88 (95 % CI 1·10, 3·22) increased odds of maintenance. Regarding individual MedDietScore components, only fruit intake is associated with increased odds for maintenance (1·03 (95 % CI 1·01, 1·06)). The leave-one-out approach revealed that at least six MedDietScore components were essential for the observed relationship. Higher adherence to the Mediterranean diet was associated with 2-fold increased likelihood of weight loss maintenance. Future studies should replicate these findings in non-Mediterranean populations as well.

Initial successful weight loss is often followed by weight regain after the dietary intervention. Compared with lean people, cellular stress in adipose tissue is increased in obese subjects. However, the relation between cellular stress and the risk for weight regain after weight loss is unclear. Therefore, we determined the expression levels of stress proteins during weight loss and weight maintenance in relation to weight regain. In vivo findings were compared with results from in vitro cultured human Simpson–Golabi–Behmel syndrome (SGBS) adipocytes. In total, eighteen healthy subjects underwent an 8-week diet programme with a 10-month follow-up. Participants were categorised as weight maintainers or weight regainers (WR) depending on their weight changes during the intervention. Abdominal subcutaneous adipose tissue biopsies were obtained before and after the diet and after the follow-up. In vitro differentiated SGBS adipocytes were starved for 96 h with low (0·55 mm) glucose. Levels of stress proteins were determined by Western blotting. WR showed increased expressions of β-actin, calnexin, heat shock protein (HSP) 27, HSP60 and HSP70. Changes of β-actin, HSP27 and HSP70 are linked to HSP60, a proposed key factor in weight regain after weight loss. SGBS adipocytes showed increased levels of β-actin and HSP60 after 96 h of glucose restriction. The increased level of cellular stress proteins in the adipose tissue of WR probably resides in the adipocytes as shown by in vitro experiments. Cellular stress accumulated in adipose tissue during weight loss may be a risk factor for weight regain.

Feline obesity is a prevalent medical disease and the main therapeutic strategy is dietary energy restriction. However, at present there are no data regarding long-term outcome in this species. The purpose of the present study was to investigate if, as in other species, some cats regain weight following successful weight loss, and to identify any influencing factors in a cohort of client-owned cats with naturally occurring obesity. Twenty-six cats were included, all of which had successfully completed a weight management programme. After weight loss, cats were periodically monitored. The median duration of follow-up was 954 d (72–2162 d). Ten cats (39 %) maintained their completion weight (±5 %), four (15 %) lost >5 % additional weight and 12 (46 %) gained >5 % weight. Seven of the rebounding cats (58 %) regained over 50 % of their original weight lost. Older cats were less likely to regain weight than younger cats (P = 0·024); with an approximately linear negative association between the cat's age and the amount of weight regained (Kendall's τ = −0·340, P = 0·016). Furthermore, cats whose energy intake during weight loss was greater were also more likely to regain weight (P = 0·023). When the characteristics of weight regain in cats were compared with those from a similar cohort of dogs, cats that rebounded were more likely to regain >50 % of the weight they had lost. These results suggest that weight regain, after successful weight loss, is common in obese cats, and that young cats (<7 years of age) are most at risk.

After having participated in a weight loss trial, most participants do not stabilise the obtained weight loss but return to their initial weight. The aim of this review is to describe the main determinants of continued low weight status after weight loss, and the effectiveness of physical activity (PA), energy restriction and macronutrient composition of the diet for low long-term weight regain. Studies with intervention periods of at least 3 months duration of weight reduction measures and a follow-up at least 2 years after the intervention period were considered as eligible for the review. Owing to limited data, the studies describing the role of PA in weight management were eligible with a follow-up of 1 year only. It appears that a diet with self-regulation of dietary intake seems to be given a prominent role in the strategy of successful long-term weight loss among the obese. This measure could be combined with behaviour therapy and PA and tailored to the individual situation. However, considering available evidence it is difficult to conclude regarding unambiguous measures and to recommend a specific dietary intervention. Nevertheless, interventions should be effective in promoting intrinsic motivation and self-efficacy. The harmonisation and standardisation of data collection in the follow-up period of long-term weight loss studies is a major challenge.

The present study investigates whether excessive fat accumulation and hyperinsulinaemia during catch-up growth on high-fat diets are altered by n-6 and n-3 PUFA derived from oils rich in either linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA) or DHA. It has been shown that, compared with food-restricted rats refed a high-fat (lard) diet low in PUFA, those refed isoenergetically on diets enriched in LA or ALA, independently of the n-6:n-3 ratio, show improved insulin sensitivity, lower fat mass and higher lean mass, the magnitude of which is related to the proportion of total PUFA precursors (LA+ALA) consumed. These relationships are best fitted by quadratic regression models (r2>0·8, P < 0·001), with threshold values for an impact on body composition corresponding to PUFA precursors contributing 25–30 % of energy intake. Isoenergetic refeeding on high-fat diets enriched in AA or DHA also led to improved body composition, with increases in lean mass as predicted by the quadratic model for PUFA precursors, but decreases in fat mass, which are disproportionately greater than predicted values; insulin sensitivity, however, was not improved. These findings pertaining to the impact of dietary intake of PUFA precursors (LA and ALA) and their elongated–desaturated products (AA and DHA), on body composition and insulin sensitivity, provide important insights into the search for diets aimed at counteracting the pathophysiological consequences of catch-up growth. In particular, diets enriched in essential fatty acids (LA and/or ALA) markedly improve insulin sensitivity and composition of weight regained, independently of the n-6:n-3 fatty acid ratio.