Table 3 Effects of diet and exercise on metabolic parameters and histopathology

	n	Year	Diet	Exercise	Duration	Weight loss	Results	F/U liver bx	Histopathology results
Diet + exercise
Baba et al83	65, 28 pts completed study with exercise and diet	2005	25 kcal/kg/day; 60% carbohydrates, 20% fat, 20% protein, 200 mg cholesterol	Brisk walking, jogging or rhythmic aerobic exercise 45 min 5 days/week (target heart rate of 60–70% max)	Minimum of 3 months	Average weight loss of 3.1 kg	Improved BMI, waist circumference, WHR, ALT, AST	No	NA
No controls; all pts with NASH	65, 28 pts completed study with exercise and diet	2005			Minimum of 3 months	Average weight loss of 3.1 kg	4–4.5% decrease in weight associated with 50% reduction in ALT	No	NA
Ueno et al87	25	1997	25 kcal/kg/day of IBW	Walking then jogging 20 min twice daily	3 months	BMI decrease of 3.0	Liver enzymes, cholesterol, fasting glucose improved	Yes	Steatosis improved
Randomised; all pts with NAFLD	25	1997	25 kcal/kg/day of IBW	Walking then jogging 20 min twice daily	3 months	BMI decrease of 3.0	Liver enzymes, cholesterol, fasting glucose improved	Yes	Steatosis improved
Kugelmas et al84	23	2003	Step 1 AHA	Walking or jogging 30 min/day	3 months	∼5%	ALT and AST, cholesterol improved	No	NA
Randomised, all pts with NASH	23	2003	Step 1 AHA	Walking or jogging 30 min/day	3 months	∼5%	ALT and AST, cholesterol improved	No	NA
Thomas et al86	10	2006	Reduction of 500 kcal/day	Walking with goal of “10 000 steps a day”	6 months	∼4%	Decreased subcutaneous (−9.9%) and intra-abdominal (−11.4%) adipose tissue; decreased intramyocellular lipid content in tibialis; decreased HgbA1c	No	NA
No controls; all pts with NAFLD	10	2006	Reduction of 500 kcal/day	Walking with goal of “10 000 steps a day”	6 months	∼4%		No	NA
Tamura et al79	7	2005	27.9 kcal/kg IBW; 60% carbohydrate, 25% fat, 15% protein	Walking 2–3 times/day for 30 min 5–6 days/week (intensity of 50–60% max O₂ uptake)	2 weeks	BMI decrease of 2.3	Decreased intramyocellular lipids, increased muscle insulin-mediated glucose uptake, decreased IHL (27%)	No	NA
Randomised to diet vs diet/exercise; all pts type 2 diabetics	7	2005	27.9 kcal/kg IBW; 60% carbohydrate, 25% fat, 15% protein		2 weeks	BMI decrease of 2.3		No	NA
Hickman et al88	31	2004	Individual counselling to achieve 0.5 kg weight loss/week. Diet based on 55% carbohydrate, 15% protein, 30% fat platform	150 min of aerobic exercise/weeks for 3 months, then encouraged to maintain routine for 9 months	12 months	4%	Improvement in ALT and insulin resistance	Yes: 14 pts 3–6 months after initial 3 months of study	Steatosis and fibrosis improved
No controls, chronic liver disease and steatosis	31	2004			12 months	4%	Improvement in ALT and insulin resistance	Yes: 14 pts 3–6 months after initial 3 months of study	Steatosis and fibrosis improved
Zelber-Sagi et al62	44	2006	104.5 kJ/day for IBW, <30% fat and simple carbohydrates	40 min walking at 5–6 km/h 3–4 times/week	6 months	8%	Improvement in ALT and AST. Significant improvement in steatosis by US in orlistat group	No	NA
Double-blind, randomised, placebo controlled; all pts with NAFLD	44	2006	104.5 kJ/day for IBW, <30% fat and simple carbohydrates	40 min walking at 5–6 km/h 3–4 times/week	6 months	8%		No	NA
Suzuki et al85	348	2005	Brochure encouraged total caloric restriction, especially fat	Increase daily activity for 20–30 min/day, 2–3 times/week	12 months	0.1% overall: 6% of cohort lost ⩾5% weit	All pts losing ⩾5% weight improved ALT	No	NA
Longitudinal cohort of pts with suspected NAFLD	348	2005		Increase daily activity for 20–30 min/day, 2–3 times/week	12 months	0.1% overall: 6% of cohort lost ⩾5% weit	All pts losing ⩾5% weight improved ALT	No	NA

AHA, American Heart Association; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; HgbA1C; haemoglobin A1C; IBW, ideal body weight; IHL, intrahepatic lipid; NA, not available; NAFLD, non-alcoholic fatty liver disease; NASH, non-alcoholic steatosis; pts, patients; US, ultrasound; WHR, waist to hip ratio.