**1. Introduction**

Consumption of phytochemical-rich foods has been shown to ameliorate some of the negative metabolic effects resulting from consumption of an obesogenic and diabetogenic, Western-style diet. Specifically, green tea contains a series of polyphenols known as catechins, mainly epigallocatechin gallate (EGCG), epicatechin gallate, and gallocatechin gallate [1]. Many of the demonstrated beneficial effects of green tea are attributed to its most abundant catechin, EGCG. One study demonstrated that EGCG treatment suppressed hyperglycemia, proteinuria, and lipid peroxidation. These results also suggested that EGCG may alleviate renal damage caused by abnormal glucose metabolism-associated oxidative stress [2]. Epigallocatechin gallate may also modulate appetite and reduce food intake [3, 4]. Furthermore, green tea catechin consumption has been shown to stimulate hepatic lipid metabolism, through mechanisms such as increased acyl-CoA oxidase and β-oxidation activity [1], as well as stimulate O2 consumption and energy expenditure [5].

These recent studies demonstrating the therapeutic potential of consuming green tea catechins have led to an interest in consuming green tea and green tea extract to remediate metabolic dysfunction. Green tea extract has been reported to stimulate brown adipose tissue thermogenesis along with fat oxidation. It was suggested that green tea's thermogenic effect may be stimulated through the interaction of its high catechin and caffeine content with sympathetically released noradrenaline [6]. In addition, a meta-analysis conducted in 2015, demonstrated that green tea drinkers have a reduced risk of liver disease including liver steatosis [7]. Epidemiological studies have also suggested that regular consumption of five to six or more cups of green tea per day has pronounced cardiovascular and metabolic health benefits [8].

It is thought that some phytochemical-rich foods may work synergistically to remediate metabolic syndrome when consumed together. Such foods of interest are fruits like red raspberries and cherries along with polyunsaturated fatty acid-rich nuts like walnuts. Cherries are rich in anthocyanins and have been previously observed to improve glucose tolerance and liver lipid accumulation [9], while bioactive polyphenols present in red raspberries may remediate oxidative stress and inflammation [10]. Walnuts have been shown to improve serum lipid levels as well as other cardiovascular parameters [11].

Part 1 of this chapter summarizes research demonstrating the changes to metabolism when consuming an obesigenic high-fat diet supplemented with walnut alone and walnut plus green tea. Some results from Part 1 were previously published, see [12]. Part 2 adds to the results from Part 1 by including a second study where four whole foods (whole cherry and red raspberry along with walnut and green tea) were consumed together to determine their synergistic effect, if any, on remediating metabolic syndrome, again, in the context of a high-fat diet provided to male mice. Both Part 1 and Part 2 studies were designed the same using a C57BL/6 J mouse strain as a model to induce obesity and study the negative metabolic effects that develop when presented with a high-calorie Western-style diet. The hypotheses of both studies were that consumption of the test foods would work to remediate metabolic complications in C57BL/6 J male mice fed a high-fat, high-sucrose, and high-cholesterol diet modeling an obesigenic and diabetogenic Western-style diet.
