Testing was performed after an overnight fast at baseline (week 0), week 10, and week 62. Participants wore light clothing and were barefoot when anthropometric measurements were made. Bioelectrical impedance was used to measure body weight and composition, with the use of a body-composition analyzer (TBF-300, Tanita). At each of these visits, the first measurement was made while the patient was fasting (baseline). A standardized breakfast was then provided, which consisted of a boiled egg, toast, margarine, orange juice, cereal biscuits (Weet-Bix, Sanitarium), and whole milk. This meal contained 2.3 MJ (550 kcal), with approximately 51% of the energy from carbohydrate, 33% from fat, and 16% from protein. Blood samples were collected 30, 60, 120, 180, and 240 minutes after the meal. Self-reported ratings of appetite were also recorded at these times with the use of a validated 100-mm visual-analogue scale.
Food prices and availability. Several studies have examined the likely impact of climate change on world food prices, mostly of grain. As reviewed by , these studies suggest little change, or a small reduction, in grain prices up to a rise in global temperatures of 3°C after which prices will start to rise as production falls. However, many assessments do not consider likely increases in the frequency of extreme weather events predicted under climate change . When these assessments are considered, concluded that crop prices are likely to be higher than the published assessments. One example of the impact of current climate variability occurred in 2006 when extreme weather in many parts of the world, particularly the Murray–Darling Basin in Australia, led to reductions in world cereal production. These yield reductions were partly to blame for rising global food prices (). Another example was the 25% reduction in the French fruit harvest after the 2003 European heat wave. Although extreme weather events have the potential to lead to localized food shortages, in the 2003 European heat wave the global food trade helped to avert regional food availability issues ().
Consuming food that is in season tends to lower GHG emissions. This is because out-of-season food production has greater agricultural inputs, such as the use of heated greenhouses, and hence GHG emissions (). If low-GHG diets lead to reduced consumption of nonseasonal produce, this could adversely affect fruit and vegetable consumption in the winter and spring when local availability is limited in temperate countries. Ensuring adequate year-round consumption of a variety of fruit and vegetables is important for public health () and has been one of the major beneficial changes in the diets of individuals over the past 40 years (). Transport of food from other parts of the world where it is in season would be one solution to this problem, as would be storing seasonally produced food for other times of the year. These two options may be similar in terms of GHG emissions. One study suggested little difference in GHG emissions between consuming European-grown apples in the spring (harvested in the autumn and stored through the winter) and consuming imported apples from New Zealand (harvested in the European spring and shipped directly to Europe) ().